VLAB-221-00050
3 Terminal Perovskite/Silicon Tandem Solar Cells
Infrastructure: EPFL/CSEM_Evatec Clusterline
Status: Finished

Our research focuses on the integration of silicon bottom solar cells featuring interdigitated back contacts (Si IBC) and perovskite top cells into highly efficient 3-terminal tandem devices. This tandem device approach is very tolerant towards spectral variations, mitigates the impact of different degradation behaviors of the two sub-cells. Therefore, at ipv, we have fabricated and characterized first Si IBC bottom cells with different front and rear side morphology and have compared their performance. Then, we deposited wide band gap (~1.7 eV) perovskite top cells wet-chemically directly onto the front surface of the Si IBC bottom cells. Conformal wet-chemical deposition of the perovskite top cell on Si bottom cells with ~5m wide-sized pyramids is challenging and displays the main bottleneck for our 3T perovskite/silicon tandem cell development. The uniform intermediate layers will allow fabrication of shunt-free tandem solar cells, thus help us to further optimize the 3T device.
VLAB-223-00078
High-purity nanoparticles for Perovskite Solar Cells Performance enhancement
Infrastructure: UNITOV_CHOSE-S2S
Status: Finished

Various nano-particle have been shown to potentially improve the performance of Perovskite solar cells. The Nanoparticles are generally produced trough wet-chemistry process, which inevitably comes with impurities such as surfactants, emulsifiers, catalysts, etc. and besides is generally complex to interface with microfabrication production equipment. In this project, the Gas aggregation process will allow the generation of high-purity NPs by a purely physical synthesis: In this process, a metallic vapor is generated by sputtering in a large aggregation volume at moderate vacuum. Fraunhofer FEP pioneered the use of Gas-Flow-Sputtering (GFS) source for this process, enabling the production of NPs from virtually any metal, including ferromagnetic metals in relatively large quantity and over large area. This process is readily applicable industrially (TRL-4).
VLAB-222-00062
Atomic Layer Deposited Buffer layers Comparison for Super-Stable Inverted Perovskite Solar cells and Modules
Infrastructure: TNO_S2S P2L
Status: Finished

With the great efforts of the photovoltaic community, hybrid organic-inorganic perovskite solar cells have reached unprecedented power conversion efficiencies (PCEs) as high as 25.7%. However, the biggest shortcoming is the instability of the devices. As a result, this study focuses on optimizing atomic layer deposition of SnOx/Al: ZnO and ZnO on top of PCBM in an inverted perovskite solar cell architecture. The p-i-n device design will be used, with a stack of Glass/ITO/PTAA/PFN-Br/Cs0.05FA0.81MA0.14PbI2.7Br0.3/PCBM/Buffer layer/ITO/Cu. We believe a comparison study of the buffer layers deemed necessary in identifying the ideal buffer layer for highly efficient and stable device. As a result of this optimization, the devices will function with improved stability. Furthermore, manufacturing on large modules demonstrates the feasibility of industrialization.
VLAB-221-00047
Physical device simulation of Silicon/Perovskite solar cell featuring HTL/ETL materials for optimizing band offsets and electrical properties
Infrastructure: CENER_MODELAB
Status: Finished

Numerical simulations via Silvaco TCAD simulator provides in-depth physics insights along with realistic observations of the design parameters that influence the PV performance of the solar cell. In this collaborative project, perovskite solar cell (PSC) will be simulated in tandem with Silicon for enhancing the PV performance. A comparative investigation for couple of electron transport layers (ETL) and hole transport layers (HTL) will be undertaken to analyze the band offsets at various interfaces as well as examine their electrical and optical properties. Various design parameters such as doping concentration, thickness of layers, defects states, and temperature variation analyses will be executed to optimize the device. For veracity of simulation studies, the PV data for a stable PSC (over one year with minimum degradation in power conversion efficiency) will be incorporated at AM 1.5 sunlight. Articles from the project will be published in reputed journals for widespread reach.
VLAB-223-00077
Learning know-how on fabrication and encapsulation of 10 cm x 10 cm perovskite modules
Infrastructure: UNITOV_CHOSE-S2S
Status: Finished

There is a huge gap between making small cells and modules. Conveniently, multiple stand alone perovskite cells (~0.1 cm square) can be made by spin coating techniques. Meanwhile, the policy makers and community at large want to see data obtained from modules at real outdoor conditions, leaving small cells tested under simulated and controlled ambient less relevant to paving way for perovskite PV to enter market. Our project aims to provide evidence of outdoor testing of solution-processed emerging PV suitable and potential for cloudy climate such as that of the UK. We clearly see VIPERLAB as an accelerator for us to establish the know-how and minimize resource waste in shifting from small cell to a minimodule 10 cm x 10 cm. By the end of our project (2024), we will also develop larger 30 cm x 30 cm modules. Instead of conducting a specific experiment, it would be a great gain for us to learn know-how and establish our baseline alike to other more experienced research groups.
VLAB-223-00075
HAXPES studies of functional perovskite interfaces
Infrastructure: HZB_XPS/HAXPES
Status: Finished

Understanding the energetics, structure and chemistry of HaP interfaces is key for developing HaP as a functional material for solar cell and light emitting diode applications. We have developed a methodology to carry out operando HAXPES measurements on working lead halide perovskite solar cells interfaces through a design of thin interface and contact layers. This would allow us to elucidate the band alignment, interface reactions and voltage losses/gains across the interfaces of perovskite solar cells with different selective contacts comparing dark and illuminated samples.
VLAB-222-00061
Large area device fabrication and quantification of degradation mechanisms
Infrastructure: UNITOV_CHOSE-S2S
Status: Finished

VLAB-231-00102
Interface-optimized hole transport materials for highly stable and efficient perovskite solar cells.
Infrastructure: UNITOV_CHOSE-S2S
Status: Finished

The interfaces of a perovskite solar cell (PSC) are crucial not only for the performance but also the stability of the device. It has been found that halo-functional hole transport materials (HTMs) can anchor to the perovskite surface creating an ordered and uniform layer, improving their resilience to degradation, as well as suppressing ion migration and recombination. This study aims to combine halogen bonding with substituents specifically designed to interact with the device electrodes, in order to further promote device stability and to extend the benefits to both conventional and inverted device structures. To this end, the two HTM variants will be synthesized with thiol and carboxylic acid groups, respectively. The fabricated PSCs are expected to become another step towards very stable and cost-effective perovskite solar cells.
VLAB-231-00093
Advancing Scalability of Semitransparent Perovskite Solar Cells for Building-Integrated Photovoltaics with Roll-to-Roll Production
Infrastructure: Juelich_R2R-Coating Line
Status: Finished

Flexible Perovskite solar cells (PSCs) have emerged as a promising technology for solar energy conversion due to their high efficiency, low-cost, lightweight, and thin characteristics. However, their scalability is a major challenge that needs to be addressed for commercialization. As the preliminary work, using of a non-toxic solvent system and low deposition temperature for the flexible all-blade coated PSCs with 14%. PCE was done. Additionally, flexible semitransparent devices using FAPbBr3 perovskite as part of the European Project CitySolar were manufactured that showed up to 60% average visible transparency and delivered 5% PCE. We propose the development of roll-to-roll (R2R) deposited perovskite solar modules using a cost-effective and robust scalable slot-die coating technique. This work can produce a highly efficient and stable semitransparent solar modules suitable for BIPV applications, opening new opportunities in the PV market.
VLAB-231-00101
Interface Formation between Metal Halide Perovskites and Oxide Films from Atomic Layer Deposition
Infrastructure: HZB_XPS/HAXPES
Status: Finished

We will use hard X-ray photoelectron spectroscopy (HAXPES) measurements to investigate the chemistry and defect formation at the interface between metal halide perovskite thin films and oxide layers grown by atomic layer deposition. We will track reactions at the buried interface and introduce interlayers that protect against the impact of the deposition process.
VLAB-231-00100
Improving the longevity of perovskite solar cells
Infrastructure: IMEC_TFPV lab
Status: Finished

By this proposal, I am asking for access to the Maximum power point tracking (MPPT) machine and laminators available in imec institution. I would need to laminate my devices and then age them under MPPT condition.
VLAB-231-00099
Fabrication of pin perovskite solar cells and modules. Characterization under outdoor and impedance spectroscopy measurements.
Infrastructure: IMEC_TFPV lab
Status: Finished

Our project aims at performing characterization experiments that would allow for a better understanding of the degradation pathways of perovskite solar cells and modules. The intention is to prepare samples of inverted perovskite solar cell with the ITO/NiO/perovskite/C60/BCP/Cu architecture, and minimodules following the same layer stack. These devices will be prepared at the TFPV infrastructure at imec. The final devices will be characterized by means of impedance spectroscopy measurements and outdoor degradation protocols.
VLAB-231-00098
STABILITY OF FLEXIBLE PEROVSKITE SOLAR CELLS
Infrastructure: HZB_MPP-Ageing
Status: Finished

Processing high-quality, flexible perovskite hybrid films require obtaining defect-free, well-coupled electrical interfaces with adjacent and equally selective contact layers. This work aims to demonstrate that flexible devices fabricated by the Slot-die Coating method in different architectures can eliminate different microscopic defects that could improve photovoltaic parameters and stability in flexible devices.
VLAB-231-00096
Stability testing of perovskite mini-modules
Infrastructure: HZB_MPP-Ageing
Status: Finished

Stability testing of several perovskite mini-modules is expected to be implemented under the high-throughput aging system located at Helmholtz-Zentrum Berlin. The modules will be exposed under different irradiance and temperature levels in a cycled light-dark analysis. This procedure will mimic the outdoor testing and will demonstrate the performance trends at the different conditions. The measurements will extract also the diurnal efficiency degradation and performance recovery values. All the aging results will be compared to those collected outdoors at University of Cyprus (UCY).
VLAB-231-00094
Comprehensive defect passivation of Sn-Pb perovskites for application in tandem solar cells
Infrastructure: ENEA_Tandem
Status: Finished

Perovskite solar cells can be easily integrated into a multi-junction (tandem) architecture, thus can easily overcome the limitations of their single-junction counterparts. For this, they can be combined with silicon, CIGS or organic solar cells or with different perovskites. In all perovskite tandem solar cells (TSCs), top (narrow bandgap, NBG) and bottom (wide bandgap, WBG) subcells must be separately optimized to enhance open circuit voltage and fill factor. In this project, we use a comprehensive defect passivation approach to reduce recombination in both subcells and at their interconnection. Due to the limitations in measuring electro-optical properties of our NBG cells at our group, we seek a collaboration with another group which has capabilities to measure quantum efficiency and photoluminescence beyond 950 nm.
VLAB-221-00046
Flexible biosusbtrates for perovskite solar cells
Infrastructure: CEA_WV P
Status: Finished

Bio-substrates have been getting attention in the recent years, due to their attractive optical and gas barrier properties. Nanocellulose has the interesting of light scattering. This would elongate the pathlengths of incoming light in solar cells, giving the light a bigger opportunity to hit the active area. Also due to their flexibility they could be used in high production techniques such as roll-to-roll manufacturing. Moreover, they are easy to dispose at the end of the device lifetime making recyclability more attractive to venture capital. We would like to use our bio-substrates to fabricate flexible perovskite solar cells using the VIPERLAB facilities and characterize their electrical and gas barrier properties. NOTE: The system does not let me add more than one instrument in technical requirements, but we need CEA_WV_P, CEA_He_P and CEA_El_Ch
VLAB-224-00089
Studying the aging effects in Hetero-structured Nb:TiO2/TiO2 based all-inorganic Perovskite solar cells
Infrastructure: HZB_MPP-Ageing
Status: Finished

Recent promising results and the prospect for obtaining temperature-stable devices by removing organic cations are generating high expectations in CsPbI3-based perovskite solar cells (PSCs). However, the JV hysteresis is large and the power conversion efficiencies (PCEs) are still lower compared to devices based on hybrid organic-inorganic perovskites. Various improvements have been achieved in PSCs by incorporating interlayers between the perovskite and the ETL. Herein, we propose a new approach consisting of the introduction of a thin (1-2 nm) 0.5% Nb:TiO2 film between the CsPbI3 perovskite and the pristine TiO2 (hetero-ETM). This approach integrates both the passivation effect observed in our previous study and an interfacial dipole between ETL/perovskite, increasing the driving force for the extraction of electrons. The aim of this study is to compare the device stability of hetero-ETM based all inorganic PSCs respect to bulk 0.5%Nb doped TiO2 based PSCs.
VLAB-224-00086
Encapsulation of Perovskite Solar Cells and Stability Testing
Infrastructure: HZB_MPP-Ageing
Status: Finished

Despite the high power conversion efficiencies above 25% achieved with lead-halide perovskites, significant commercial success is yet to be witnessed with perovskite solar cells (PSCs) due to insufficient stability of these devices. Device encapsulation, essential for commercialization, is still a challenge and the range of possible techniques is limited by several factors including high chemical sensitivity of PSC materials and low tolerance to elevated temperatures during the encapsulation. This research stay at HZB will focus on encapsulation with n-i-p structure. During this visit, PSCs fabricated at ICN2 will be encapsulated using 3 encapsulation strategies both at home and host laboratories. These experiments will be important to validate previous results obtained at ICN2 regarding the performance of different methods of encapsulation. Once the quality of encapsulation is confirmed in climate chambers, the devices will be used for outdoor experiments in Berlin and Barcelona.
VLAB-224-00085
Numerical simulation of a free-HTL perovskite FASnI3-based solar devices
Infrastructure: CENER_MODELAB
Status: Ongoing

In the work, novel free-HTLs will be designed using the simulator to explore their potential and performance for HTL-free PSCs. In order to obtain optimal device performance, several device parameters, including the thickness, doping concentration, and defect density for the absorber and also other layers will be investigated.
VLAB-224-00084
Interface engineering of perovskite/hole transport layer using small organic molecules for efficient and stable perovskite solar cells.
Infrastructure: Fraunhofer_nanoPSC
Status: Finished

Improving the efficiency and stability of perovskite solar cells (PSCs) is essential to accelerate the pursuit of carbon neutrality. Interface engineering has become one of the rewarding approaches to control the charge accumulation and recombination at interfaces, which in turn promotes excellent charge extractability and cell performance. Here, we will introduce a small organic molecules based on benzylidene-malononitrile (DABMN) as an interfacial layer placed on a perovskite to minimize the energy barrier and charge accumulation at the interface to intensify the extraction of detrapped charges and charge transfer dynamics. The effect of the concentration of DABMN interfacial layer in microstructure and optical-electrical properties will be assessed.
VLAB-224-00083
Investigating the root causes of PID of different perovskite solar cells concerning encapsulants
Infrastructure: Fraunhofer_nanoPSC
Status: Finished

Potential-induced degradation (PID) can severely limit the lifetime of solar cells. In the case of silicon cells, it was possible to understand the causes of PID and to avoid it by technological changes. However, it is very likely that perovskite solar cells (PSCs) will also be affected by the phenomenon. Even though the stability of PSCs under elevated temperature and irradiation has been investigated by several studies, there is only limited data on PID. To the author's best knowledge, only three papers have been published, and they all indicated the degradation of PSCs under high voltage stress [1] [3]. With the limited knowledge and the lack of PID test standardization, efficient measures against PID in PSCs remain unknown. In this study, the possibilities of accelerated PID tests of PSCs and the PID sensitivity of different PSCs with varying encapsulants will be investigated through a postmortem root cause analysis.
VLAB-224-00082
Study of the structural, electronic, and optical properties of a Zn-doped FABI3 (B=Sn, Ge)solar perovskite for photovoltaic application.
Infrastructure: ENEA_CRESCO HP
Status: Finished

Here, i propose to study the Hybrid-organic-inorganic Zn doped FASnI3 and FAGeI3 perovskite for photovoltaic application. In fact, I will investigate and discuss the structural, electronic (band structure, band gap energy value), and optical properties of this solar perovskites photovoltaic material using the DFT method implemented in the Quantum Espresso package.
VLAB-223-00081
Fabrication of PSCs by R2R slot-die coating process under ambient atmosphere using green solvents
Infrastructure: SU_PV Manu & Test
Status: Finished

Perovskite solar cells are one of the most promising photovoltaic technologies, with an astonishing development within a very short time. The next step towards commercialization is to make this technology compatible with largescale production. One attractive method is the roll-to-roll (R2R) slot-die coating process, in which the active layers are continuously deposited on a large area flexible substrate, ideally under ambient atmosphere. However, the typical solvents used for the perovskite solution are toxic (e.g. DMF, NMP), which raises serious environmental and health concerns. At SAULE we are currently testing greener alternatives and our current best recipe for blade-coating deposition under ambient atmosphere is based on ACN, 2-ME and DMSO with ionic liquid additive, but ultimately it is intended to use only green solvents. The aim of this study is to transfer the already optimized perovskite blade-coating process to a R2R slot-die process, without losing perovskite quality.
VLAB-223-00076
Interfacial engineering of eco-friendly low-cost inorganic HTMs for perovskite solar cells
Infrastructure: UNITOV_CHOSE-S2S
Status: Finished

Solar energy is one of the promising technologies for clean energy production. In the last decade, the photovoltaic industry has witnessed a skyrocketing growth in the power conversion efficiency of organic-inorganic perovskite solar cells (PSCs) from primal 3.8% to a confirmed 25.7%. Spiro-OMeTAD is the most commonly developed Hole-transporting material (HTM) with an expensive complicate synthesis. Besides, it needs hygroscopic doping that reduces the stability of device. To meet the necessities for future commercialization, eco-friendly low-cost HTMs have been widely investigated and studied. P-type Cu-based chalcogenide semiconductors are promising substitute because of high mobility and low cost synthesis processes. However, their efficiency is lower than the value obtained from the expensive competitor, Spiro-OMeTAD. It has been well evidenced that apart from the importance of composition and microstructure of heart of device, perovskite active layer, interfacial optimization of c
VLAB-223-00068
Preparation and characterization of sequentially evaporated (Cs,FA)Pb(I,Br)3 perovskite solar cells
Infrastructure: SU_PV Manu & Test
Status: Finished

We prepare sequentially evaporated (Cs,FA)Pb(I,Br)3 perovskite layers on an ITO/PTAA substrate. These samples are post-annealed at 100C to complete the interdiffusion and layer reaction. We aim to investigate the effect of different sequencing of the components FAI, CsI, PbI2 and PbBr2 on the interface reactions during processing and find advantageous interface species for cell preparation. These effects are scarcely studied. Our sequentially deposited perovskite layers will be processed to complete solar cells in a p-i-n structure in a VIPERLAB facility, where standard cell characterization will also be performed. The transport from our lab to the VIPERLAB facilities will be ensured in a nitrogen atmosphere. Wet-chemical reference cells will also be prepared.
VLAB-223-00063
FLEXPERCIS Flexible Perovskite/CI(G)S Tandem Solar Cells for Integrated Photovoltaics
Infrastructure: TNO_S2S P2L
Status: Finished

Sunplugged develops flexible CIGS-PV modules for integrated photovoltaics. Sunpluggeds made-to-measure photovoltaic foil is based on three proprietary technologies combined in one unique approach: (1) a band-gap tunable solar cell process, (2) a digitally controllable serial interconnection that allows customer oriented production on-the-fly and (3) a flexible substrate that facilitates ultra-thin, lightweight and stable packaging. In order to achieve significantly higher efficiencies tandem devices are a very promising concept. The main objective of the project is to investigate the feasibility and viability of a high efficient, 2-terminal (2T) thin-film multi-junction perovskite/CIGS solar cell which builds upon the established technologies. The flexible thin-film perovskite/CIGS tandem devices will bring a substantial performance boost to Sunpluggeds offerings whilst the unique features like made-to-measure production and lightness can be maintained.
VLAB-223-00073
Using TCAD simulations to optimize 2T Tandem Perovskite-Cu(In,Ga)Se2 solar cells
Infrastructure: CENER_MODELAB
Status: Ongoing

The maximum conversion efficiency a single junction solar cell can achieve is determined by its band gap, and is hence inherently limited by photon thermalization and transmission. Multiple-junction solar cells provide an opportunity to surpass the efficiency given by the Shockley-Queisser limit via a more optimized usage of the solar spectrum. A tandem structure consisting of the perovskite/CIGS combination is very promising for several reasons: i) both materials have high absorption coefficients and long diffusion lengths, ii) both absorbers have tunable band gaps which cover the ideal values of 1.7-1.9 eV for the top cell and 0.9-1.2eV for the bottom one iii) both devices have separately achieved high conversion efficiencies, and iv) both solar cells are thin-film structures allowing a possibility for flexible applications. An optimization of the tandem structure requires detailed measurements and an accurate interpretation of the data.
VLAB-223-00074
p-Doping of organic semiconductors for stable and efficient perovskite solar cells
Infrastructure: IMEC_TFPV lab
Status: Finished

Solution-processed perovskites enabled high efficiency photovoltaic cells. In these devices, organic semiconductors (OSCs, e.g., spiroOMeTAD, PTAA) are used as charge transport layers. To this end, stable and efficient molecular dopants have been developed to improve the efficiency as well the environmental stability of perovskites solar cells. In this project, we seek to develop Lewis acid doped hole transporting layers by using a suite of wet-lab facilities and characterization techniques at IMEC(Belgium) to gain insights into the morphology-stability-property relationships. In addition, we will correlate these findings with the structural analysis obtained from solid-state NMR and EPR spectroscopy (experiments will be carried out at Lille University, France), and hence provide insights into doping mechanisms and efficiencies of contact layers in perovskites solar cells.
VLAB-223-00072
Computational study of lead-free superlattice perovskite for photovoltaic technology
Infrastructure: ENEA_CRESCO HP
Status: Ongoing

The objective of our research is to develop a novel perovskite solar cell, composed of a low-dimensional lead-free perovskite material with a superlattice of two organic-inorganic crystal structures. For this, we will study profoundly their electronic, optical and quantum transport properties2. DFT calculations via the wien2k package and Quantum Espresso - will be used to evaluate the properties of the 2D, and 3D perovskite structures and subsequently the superlattices composed of inorganic and organic perovskites in this study. The band gap of the superlattice is refined by increasing the thickness of the perovskite layer. As an expected result, the valence band maximum and conduction band minimum states of the superlattice are separated on different atomic levels, minimizing electron and hole recombination, which is advantageous for carrier separation and charge collection.
VLAB-223-00066
Optoelectronic characterization of perovskite mini-modules
Infrastructure: AIT_Testing
Status: Finished

The proposed work aims to explore a novel approach for the measurements of the spectral response of mini-modules. The novel approach will utilize strip illumination so as to avoid the necessity of illuminating the whole device. In addition to this, measurement of the performance of several perovskite mini-modules will be conducted as part of an inter-comparison campaign between the host organization (AIT) and the University of Cyprus (UCY). Spatially-resolved techniques (Electroluminescence, Photoluminescence and Lock-In Thermography will be utilized for the characterization of the modules as well.
VLAB-223-00070
Elucidating ultra-fast charge transfer in CsPbBr, the effect of nanocrystals and transition metal dichalcogenides
Infrastructure: HZB_XPS/HAXPES
Status: Finished

Perovskite nanocrystals have shown great promise as light harvesting material for solar cells. Preliminary studies show that charge transfer occurs in at different time scales in CsPbBr3, from nanoseconds to a few femtoseconds. The charge transfer is also different between nanocrystals and bulk material and is shortened when in contact with a transition metal dichalcogenide. We propose to use core-hole clock spectroscopy to study the ultra-fast charge in bulk and nanocrystals of CsPbBr3 and try to quicken the charge transfer in the nanocrystals by introducing a transition metal dichalcogenide.
VLAB-223-00069
Tandem perovskite/silicon solar cells : Evaluation of silicon surface topography on performances of tandem devices.
Infrastructure: EPFL/CSEM_Lesker
Status: Finished

The most important R&D challenge of photovoltaic domain is today the elaboration of the next generation of highly efficient solar cells based on perovskite/silicon tandem architecture. In the literature, most of these perovskite/silicon tandem solar cells are elaborated on CMP (chemically and mechanically polished surface) silicon wafers. This configuration is actually not compatible with an industrial development. Very recently CSEM/EPFL demonstrate the elaboration of perovskite/silicon tandem solar cells on standard texturized surface reaching high efficiency up to 31.25 % in combinaison with the use of a specific conformal process for the deposition of the perovskite layer. The goal of the scientific case proposed here is the elaboration of perovskite/silicon heterojunction tandem solar cells with an optimised and industrially compatible surface texturation.
VLAB-223-00065
Advanced imaging for perovskite solar cells
Infrastructure: Fraunhofer_charPSC
Status: Finished

Combining the expertise between two photovoltaic characterisation teams at the Australian National University (ANU) and Fraunhofer-ISE, we aim to develop a series of imaging methods to spatially resolve critical optical and electrical parameters of perovskite solar cells and materials. Particularly, the project will focus on light-based imaging techniques for implied open circuit voltage iVoc and its temperature coefficient, ideality factor nid, activation energy Ea of recombination, sub-bandgap absorptivity, minority carrier lifetimes, and posiibly series and shunt resistances for various perovskite structures. It may also adopt some of these mentioned techniques to characterise subcells in silicon-perovskite tandem solar cells.
VLAB-222-00059
Selective contacts based on chalcogenides and calco-halides for peroskite solar cells
Infrastructure: UNITOV_CHOSE-S2S
Status: Finished

Recent experimental results demonstrates the potential of thin film chalcogenides as selective contacts for high efficiency solar cells. One of the main advantages of this family of materials is the ability to easily tune the bandgap as well as the bands position, to be a highly selective contact for holes or electrons. In this work we propose to investigate a new clase of low-dimensional chalcogenides (Sb2(S,Se)(3) and chalcohalides (SbSe(Br,I)) deposited by co-evaporation techniques as selective contacts in perovskite technologies. These materials have shown a high flexibility in terms of bands design, as well as control of the conductivity from n to p-type. These selectives contacts will be prepared by co-evaporation at UPC, and then tested at UNITOV partner of VIPERLAB innitiative, to demonstrate the first selective contacts based on low dimensional chalcogenide and chalco-halide compounds for perovskite. Solar cell devices will be fabricated and fully characterized.
VLAB-222-00060
Slot-die coating of PTAA and Perovskite film on plastic foils
Infrastructure: UNITOV_CHOSE-S2S
Status: Finished

Perovskite solar cells (PSCs) have already shown their potential to commercialize in the near future. However, more research focus on scalability and stability is required to accelerate a faster entry. Recently, the blade coating technique shows promising results in small area module fabrication in the laboratory. However, one main disadvantage is its incompatibility to scale with high throughput and yield. Therefore, this research focuses on optimizing PTAA (hole transport layer) and perovskite film by slot-die coating technique. We will utilize the p-i-n device configuration with a stack consisting PET/ITO/PTAA/Cs0.17FA0.83Pb(I0.9Br0.1)3/C60/BCP/Cu. Thereby the devices will perform with better stability and negligible hysteresis without using dopants for transport layers. Furthermore, fabricating on a flexible substrate provides an advantage in utilizing the roll-to-roll industry scale technique.
VLAB-222-00058
Investigation of Hysteresis in all-inorganic perovskite solar cell
Infrastructure: CENER_MODELAB
Status: Finished

The efficiency of perovskite based solar cells have increased exponentially till 25.8% over a span of 12 years, which is the highest recorded efficiency evolution for any group of materials. Despite the stellar optoelectronic properties of the group of materials, there are stability issues that hampers the realisation of perovskite solar cells for long-term usage. Though lead-based perovskites have been proven to withstand ambient situations compared to other perovskites, the lead part gives rise to toxicity problem. In order to combat these problems, cesium based lead-free inorganic perovskites have been explored as solutions. The current proposal is intended to simulate lead-free CsGeI3 based all inorganic perovskite solar cells. Further, the work also intends to identify inorganic ETLs and HTLs so as to alleviate all elements inducing stability problems in the device configurations for ambient functioning.
VLAB-222-00057
Synthesis of a Hole Transporting Material for perovskite solar cells
Infrastructure: UNITOV_CHOSE-MATERIALS
Status: Finished

Impressive improvements were done on Perovskite Solar Cells (PSCs) the last few years, achieving 25.7%, making them very competitive compared to other inorganic technologies. However, the stability of PSCs still needs to be addressed for industrial production Development of interfacial layers (for Electron Transport and Hole Transport) is a key parameter. Salts used as dopants for Hole Transporting Materials (HTMs) are highly hygroscopic, favouring the degradation of the Perovskite layer. To overcome this issue new low dopant or dopant-free conductive HTMs, with passivation properties towards the active layer to reduce the degradation induced by light and extrinsic factors can be proposed. Carbazole/phenothiazine based small molecules demonstrated favourable structural and energetical features for application in PSCs. Access the VIPERLAB infrastructure will be an opportunity to take benefit of synthetic skills on these scaffolds to prepare and characterize a new molecule HTM.
VLAB-222-00056
Assessment of low temperature printable carbon electrodes for perovskite solar cells
Infrastructure: TNO_S2S P2L
Status: Finished

Perovskite solar cells (PSCs) have the potential to become key players in the solar energy market, due to their high efficiencies, short energy payback time and versatility of applications. Highly efficient opaque PSCs employ metals as top electrodes, which increase the overall cost of the device, are not suitable for large scale manufacturing and have a detrimental effect on the cell stability. Developing low cost, metal-free, stable electrodes is therefore crucial to enable the commercialization of PSCs. In this proposal, Dyenamo will provide a commercially available low temperature printable carbon-based paste. This material will be tested at TNO as electrode for perovskite solar cells fabricated by large area compatible methods, such as slot die coating. Deposition of the electrode will be carried out by screen printing on 6 inch samples. Uniformity of the layer will be assessed and the performance of the cells evaluated under standard testing conditions.
VLAB-221-00044
Photostability of laser annealed MAPbI3 under different spectral regions.
Infrastructure: CEA_PK T
Status: Finished

Organic Inorganic Halide Perovskites (OIHPs) solar cells have shown power conversion efficiencies (PCE) up to 25.6% on a lab scale. However, one of the challenges in large-scale manufacturing of solution-based perovskite solar cells (PSCs) is to prolong uniform heat treatment of the wet perovskite film over a large surface. One possibility is laser annealing as an alternative to conventional thermal treatment. Along with upscaling, Light Induced Degradation (LID) of PSCs under the operating conditions is one of the major bottlenecks towards commercialization. However, a detailed overview is lacking on the effect of various spectral regions of sunlight on PSCs fabricated outside the N2 filled glove boxes. In this work, we would study the stability of our laser annealed PSCs as compared to thermally annealed PSCs.
VLAB-221-00043
Encapsulation and stability/aging measurements on All-inorganic perovskite solar cells
Infrastructure: CEA_PK T
Status: Finished

All-inorganic perovskites have emerged as promising photovoltaic materials due to their superior thermal stability compared to their heat-sensitive hybrid organic-inorganic counterparts. Unfortunately, the poorer phase stability at the ambient condition, i.e., humidity and oxygen, compared to organic-inorganic counterparts, is the most dominant challenge that needs to be addressed for further development. Nevertheless, this negative property is a significant obstacle to measuring photovoltaic characteristics of all-inorganic perovskite solar cells (PSCs) under ambient conditions. We are currently trying to apply some composition engineering all-inorganic CsPbI2Br composition to improve the efficiency and stability of this kind of solar cell. Therefore, our goal is to study the device stability/aging for capsulated and unencapsulated all-inorganic PSCs with different perovskite compositions, expecting different results for every condition. This characterization will help us to determine
VLAB-221-00042
Highly Efficient and Stable Large Area Flexible Perovskite Solar Cells Enabled by Cross-Linkable Silane Doping of Fullerene Derivative.
Infrastructure: UNITOV_CHOSE-S2S
Status: Finished

Fullerenes have sparked a lot of attention in recent years as a way to improve the existing high-performing p-i-n perovskite solar cells. Most the pristine fullerenes, display issues with layer morphology, device stability, and performance. Therefore, the introduction of dopants in fullerenes has been demonstrated multiple times to be beneficial by reduced transport losses, and decrease the charge-injection barrier at electrodes, resulting from the position shift of Fermi level relative to the carrier level. In this work, new cross-linkable silanes based on halide alkylammonium salts (HAS) are investigated in terms of the chemical structures by various spectroscopy techniques and via computational simulations. Furthermore, flexible perovskite solar cells were fabricated by incorporating three different silanes into the fullerene derivative, with efficiencies surpassing 19% on 1cm active area.
VLAB-221-00041
Study of the structural,electronic and optical properties of a new high efficient silicon-based perovskite using computational method.
Infrastructure: ENEA_CRESCO HP
Status: Finished

Here,i propose to study the Hybrid-organic-inorganic new silicon-based perovskite for photovoltaic application. In fact, i will investigate and discuss the structural,electronic (band structure,band gap energy value) and optical properties of the solar perovskites photovoltaic material FASiX3 (X=I or Br ) using the DFT method implemented in the Quantum Espresso package.
VLAB-221-00040
CALIBRATION OF COMPACT IN-SITU QUANTUM YIELD MEASUREMENT SETUP FOR MONITORING OF RADIATION INDUCED DAMAGE IN TANDEM-SOLAR CELLS
Infrastructure: Fraunhofer_charPSC
Status: Finished

Goal of the proposed experimental work is the verification and calibration of a selfmade (UNISA) setup, developed for the measurement of the point-wise quantum yield spectrum in-situ during the exposure of Perovskite based Tandem solar cells to energetic particles and radiation. Some Perovskite based TANDEM solar cells, have been shown to be extremely stable under Proton irradiation and are hence good candidates for future thin-film space photovoltaics. The setup, based on LED excitation at different wavelengths and conversion of the generated photocurrent in a proportional frequency has been already successfully tested for the in-situ degradation monitoring of crystalline silicon solar cells under high energy proton irradiation under vacuum. In the moment we work on the modification of the setup for the characterization of TANDEM solar cells. It would be necessary however to calibrate the system and the FHI-ISE solar cell characterization facilities would be the ideal place for this.
VLAB-221-00039
Stability test to evaluate interfacial engineering in MAPbBr3 PSCs
Infrastructure: SU_PV Manu & Test
Status: Finished

The interfaces in perovskite solar cells play a vital role in the stable performance of the devices. Especially the electron selective layer TiO2 is active in the UV region and causes a degradation at the interface. Our work on doping of TiO2 shows an increase in overall device performance. From initial impedance spectroscopy measurements, it is accessed that the device has low hysteresis and higher Voc caused by lower ion migration in the cell. We will perform the stability test of our devices with modified TiO2 to assess its effect on long-term device performance. The specific norm IEC TR 63228:2019 testing is selected for the long term stability to guarantee the performance of TiO2 modified. This analysis expects to check if interfacial engineering increases the PSCs' stability.
VLAB-211-00034
A photoelectron spectroscopy investigation of the electronic and chemical structure profile of the interface between ALD processed SnO2 and metal halide perovskite
Infrastructure: HZB_XPS/HAXPES
Status: Finished

Perovskite solar cells (PSCs) have recently exceeded 25% conversion efficiencies approaching the single-cell efficiency limit. However, there is still room for improvements. Specifically, the stability and performance of perovskite solar cells can be related to the chemistry of the interfaces between the perovskite absorber and the charge transport layers (CTLs). In this view, replacing the currently used organic CTLs, which introduce optical parasitic absorption, shunting pathways and have poor mechanical properties, for inorganic based CTL could further improve the performance of PSCs. However, when a thin film deposition technique such as atomic layer deposition (ALD) is used to grow the electron transport layer directly on the absorber, it induces chemical modifications which lead to poor performing devices. In this study, we are going to evaluate the electronic and chemical profile of the interface between the ALD-grown SnO2 and a Cs0.15FA0.85Pb(I0.92Br0.08)3 perovskite absorber.
VLAB-211-00033
Wide band gap perovskite solar cell
Infrastructure: IMEC_TFPV lab
Status: Finished

The aim of this proposal is to develop wide band gap perovskite solar cell, to be integrated later in the top of silicon heterojunction solar cell. First, we will focus on reproducing good quality FAPb(Ix,Br 1-x)3 perovskite absorber in the IMEC process. Then, the best wide band gap FAPb(Ix,Br 1-x)3 perovskite absorber will be incorporated in the IMEC stack as a reference p-i-n perovskite solar cell with Cu electrode. The resulted perovskite solar cells will be characterized by IV-measurements and MPP tracking. Based on the previous result we can optimize further the efficiency of the perovskite solar cell by adapting the p and n interfaces to have better energy level alignment, by adding other thin films. Afterwards, the best resulted solar cell with the best p- and -n-side interface materials will be used in the same stack with ITO top-electrode done by soft sputtering. Finally, we will perform IV-measurements with Si-bottom cell to determine how such tandem stack performs.
VLAB-211-00032
Logically Design Tailor-made Polymer Additives Towards Achieving Highly Stable and Efficient Perovskite Solar Cells
Infrastructure: IMEC_TFPV lab
Status: Finished

Manipulation of the defective grain boundaries and pinholes in perovskite films is crucial to maximizing optoelectronic properties and stability of the perovskite solar cells (PSCs). It has been found that by introducing polymers to perovskite films, one may improve the crystallinity and morphology of the films. The various functional groups make it possible for the polymers to control over the morphology, passivate the trap states at grain boundaries, and improve carrier mobility. The aim of the study is to design such polymers in order to favour crystallization and reduce the trap states. By using controlled radical polymerization, copolymers will be synthesized which are capable of building hydrogen bonds with perovskite. The resulted PSCs are expected to be a part of the solution for obtaining highly stable and efficient solar cells.
VLAB-211-00028
Stability of perovskite based tandem solar cells under thermal cycling for space applications
Infrastructure: EPFL/CSEM_Lesker
Status: Finished

Perovskite semiconductors have been reported to demonstrate high resilience to high energy radiation which has lead to a studies on their suitability in multijunction solar cells for space applications. This is in particular motivated by additional benefits such as a potentially lower cost for deposition of the perovskites and higher specific power. However, photovoltaics in space also undergoes thermal cycling where the temperatures vary between 373 K and 173 K. Therefore, any significant mismatch in thermal expansion in the layers within the device can result in catastrophic mechanical failure of the photovoltaic modules. Through this application, access to the EPFL/CSEM PV LAB/PV CENTER (LARGE AREA) PSK/SI TANDEM PROCESSING infrastructure is requested for fabrication of perovskite/silicon tandem cells and reference single junction perovskite solar cells. These will be evaluated for their optoelectronic and mechanical characteristics under thermal cycling at Surrey.
VLAB-211-00021
Two-dimensional MXenes for stabilization of large area perovskite solar cells and modules
Infrastructure: UNITOV_CHOSE-S2S
Status: Finished

In this proposal I would use the VIPERLAB infrastructure CHOSE-S2S for study the stabilization effect of two-dimensional MXenes based on Ti, V, Nb and Mo for large area perovskite solar cells and modules. I propose to consider the impact of MXenes as dopant for the perovskite absorber as well as interlayer. Stabilization will be assessed by using light soaking.
VLAB-211-00029
Synthesis and characterization of the small molecule 3,3'-(9-hexyl-9H-carbazole-3,6-diyl)bis(10-hexyl-10H-phenothiazine) to study its use as a Hole Transporting Material.
Infrastructure: UNITOV_CHOSE-MATERIALS
Status: Finished

Since CHOSE@UNITO (UNITOV, CHOSE-MATERIALS) is experienced with reactions on the phenothiazine scaffold, 3,3'-(9-hexyl-9H-carbazole-3,6-diyl)bis(10-hexyl-10H-phenothiazine) will be synthesized starting from the already prepared 3,6-dibromo-9-hexyl-9H-carbazole. The molecule will be structurally characterized (NMR, GC, MS analyses) and its optoelectronic properties will be investigated (UV, fluorescence analysis) as well as its electrochemical properties (CV). Moreover, the resistance to moisture is going to be probed by contact angle measurements. These analyses will enable to understand if the synthesized small molecule can be used as dopant-free Hole Transporting Material in Perovskite Solar Cells.
VLAB-211-00027
Automated formulation and analysis of perovskite composition
Infrastructure: Juelich_AMANDA
Status: Finished

Atinary Technologies aims to deploy its Self-driving Lab platform -SDLabs- to accelerate the formulation, analysis and stability testing of perovskite composition. Atinary will provide the software backbone to integrate various robotics, database, data analytics and proprietary ML algorithms into a closed-loop experimentation system. The overall experiment follows a three-step process -Design, Make and Test- orchestrated and driven by Atinarys SDLabs in the cloud. This allows remote control of the experiments, from anywhere on any devices.
VLAB-211-00026
Variation of iodide/bromide ratio in perovskite films and devices for the use in tandem solar cells
Infrastructure: Juelich_AMANDA
Status: Finished

We have developed a fabrication route for perovskite films that allow substantial changes in the band gap of the semiconductor, by simply changing the iodide/bromide ratio in the precursor solution. A detailed analysis of various compositions of the photo absorber can provide further insights of efficiency limiting phenomena. Additionally, investigation of alternative hole transporting layers can reveal information about perovskite crystal growth and trap state formation. An automated process reduces the fabrication time for a large number of samples, which are essential for detailed analysis of phenomena like mentioned before.
VLAB-211-00023
Characterization of polymer materials for optimization of perovskite solar cell encapsulation
Infrastructure: CEA_PK T
Status: Finished

To tackle extrinsic instability issues of Perovskite solar cells (PSCs), teams in HZB and CEA both developed a glass-glass encapsulation based on a butyl edge sealant and a polymer encapsulant. Both encapsulation strategies processed by vacuum lamination enable their PSCs to pass the IEC 61215 damp heat test. The aim of this collaboration between CEA and HZB is to evaluate the encapsulation materials used in both institutes through specific methods developed at CEA and characterization tools available there. Additionally, the effect of the process temperature on the barrier properties of the polymer encapsulants would be studied. The results of the experiments would enable us to optimize our encapsulation strategy and potentially lower the process temperature, thus widening the range of devices that can be laminated. Finally, this project would allow both teams in HZB and CEA to exchange knowledge and experience on the topic of encapsulation and stability of perovskite solar cells.
VLAB-211-00024
Spectral converting materials modified perovskite solar cells: Effect of light stress, damp heat and thermal cycling.
Infrastructure: IMEC_TFPV lab
Status: Finished

We are developing and studying the effect of spectral converting materials in perovskite solar cells to expand the utilization of solar spectrum. This will be conducted by Down conversion (DC) of UV-blue energy to the sub-bandgap energy of perovskite. The incorporation of these materials also affects device stability and therefore the critical lifetime assessment under defined protocol, i.e. applied stress tests of 1000 hours continuous illumination at one sun (light soak test) and 1000 hours exposure to a high humidity (relative humidity of 85 %) combined with exposure to a temperature of 85 oC (damp-heat test) is necessary to understand their role in improving lifetime of the modified devices. These stability tests in corroboration with other optoelectronic studies will help to understand and improve the efficacy of the DC materials.
VLAB-211-00022
PL and EL imaging on perovskite single crystals
Infrastructure: CEA_Adv Ch
Status: Finished

The metal halide perovskite single crystals are one of the promising materials for X-ray detection and scintillators. However, these kinds of single crystals have different optoelectronic properties on different surfaces and in the bulk of the single crystal. It is observed a redshift in Photoluminescence on edge than the center of the perovskite. We observed that the single crystals grown with and without initial seed layers show different Photoluminescence responses. Therefore our objective is to study the PL and electroluminescence (EL) response over the entire surface of these single crystals grown by these two methods. We expect to see the variation in overall PL and EL. This data set may lead us to determine which kind of single crystals have higher radiative recombination centers. Also, in the long run, it will be helpful to design single crystals for specification applications.
VLAB-211-00017
Assessment of polyolefin based encapsulants for perovskite PV
Infrastructure: TNO_S2S P2L
Status: Finished

It is well known that external factors like oxygen and moisture can significantly reduce the stability of perovskite solar cells and modules. Moreover, the additives used in the encapsulant might lead to perovskite degradation. For this reason, it is critical to provide a proper encapsulation that will protect the cells from the environment and do not compromise their performance and stability. The results of the experiment will answer questions if the specific thermoplastic polyolefin encapsulants used for c-Si modules are also suitable for encapsulation of perovskite-based modules. If not, the experiment may provide first indications of what needs to be modified. The obtained knowledge will help in the development of stable perovskite modules for research purposes and towards the commercialization of perovskite-based PV products.