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Wide bandgap halide perovskite materials show promising potential to pair with silicon bottom cells. To date, most efficient wide bandgap perovskites layers are fabricated by spin coating, which is difficult to scale up. Here, we report on slot die coating for an efficient, 1.68 eV wide bandgap triple halide 3halide perovskite absorber, Cs0.22FA0.78 Pb I0.85Br0.15 3 5 mol MAPbCl3. A suitable solvent system is designed specifically for the slot die coating technique. We demonstrate that our fabrication route is suitable for tandem solar cells without phase segregation. The slot die coated wet halide perovskite is dried by a nitrogen N2 knife with high reproducibility and avoiding antisolvents. We explore varying annealing conditions and identify parameters allowing crystallization of the perovskite film into large grains reducing charge collection losses and enabling higher current density. At 150 C, an optimized trade off between crystallization and the PbI2 aggregates on the film s top surface is found. Thus, we improve the cell stability and performance of both single junction cells and tandems. Combining the 3halide top cells with a 120 amp; 956;m thin saw damage etched commercial Czochralski industrial wafer, a 2 terminal monolithic tandem solar cell with a PCE of 25.2 on a 1 cm2 active area is demonstrated with fully scalable processes

We here present a generic methodology enabling the accelerated optimization of the composition and processes conditions for functional solution-processable materials compatible with later transfer of optimized conditions to scaled device manufacturing. In combinatorial slot-die coating, two or more precursor inks are fed with different rates into the slot-die enabling fast screening of the precursor solution composition on coating property in one experimental run, which can either be implemented as consecutive coatings with different compositions or as a continuous compositional gradient. As a first example, we here present combinatorially slot-die coated halide perovskite thin-films ranging from the precursor compositions of pure formamidinium lead iodide, FAPbI3, to methylammonium lead bromide, MAPbBr3. In this series, both the optical and morphological properties of the deposited thin-films change dramatically. An increasing faction of MAPbBr3 resulted in larger optical bandgaps. At very high MAPbBr3 ratios, differences in the thin-film crystallization kinetics due to the simultaneous change of the precursor solution solvent resulted in thin-films with low quality morphology. The spatial compositional homogeneity of the coated thin-films was characterized by grazing incidence wide angle X-ray scattering mapping. We fabricated inverted perovskite solar cells in the full compositional range and found a performance maximum for FAPbI3-richer devices with a MAPbBr3-content of 20 mol%. The performance maximum can be rationalized with the improved thermodynamic stability of the halide perovskite crystal structure due to a more ideal tolerance factor upon incorporation of the smaller methylammonium cation and bromide anion into the crystal structure. At high MAPbBr3-content, the device performance drops due to two effects: light-induced phase-segregation and a dramatically decreased thin-film morphology exhibiting pinholes. The example highlights the critical balance of precursor solution composition and processing conditions as the crystallization kinetics critically affect the resulting thin-film quality and morphology. This generic methodology can be further optimized and exploited to identify optimal precursor solution compositions and process conditions to achieve high-quality thin films with a target composition and sample morphology with high experimental throughput.

Perovskite solar cells PSCs have shown great potential for next generation photovoltaics. One of the main barriers to their commercial use is their poor long term stability under ambient conditions and, in particular, their sensitivity to moisture and oxygen. Therefore, several encapsulation strategies are being developed in an attempt to improve the stability of PSCs in a humid environment. The lack of common testing procedures makes the comparison of encapsulation strategies challenging. In this paper, we optimized and investigated two common encapsulation strategies lamination based glass glass encapsulation for outdoor operation and commercial use COM and a simple glue based encapsulation mostly utilized for laboratory research purposes LAB . We compare both approaches and evaluate their effectiveness to impede humidity ingress under three different testing conditions on shelf storage at 21 C and 30 relative humidity RH ISOS D1 , damp heat exposure at 85 C and 85 RH ISOS D3 , and outdoor operational stability continuously monitoring device performance for 10 months under maximum power point tracking on a roof top test site in Berlin, Germany ISOS O3 . LAB encapsulation of perovskite devices consists of glue and a cover glass and can be performed at ambient temperature, in an inert environment without the need for complex equipment. This glue based encapsulation procedure allowed PSCs to retain more than 93 of their conversion efficiency after 1566 h of storage in ambient atmosphere and, therefore, is sufficient and suitable as an interim encapsulation for cell transport or short term experiments outside an inert atmosphere. However, this simple encapsulation does not pass the IEC 61215 damp heat test and hence results in a high probability of fast degradation of the cells under outdoor conditions. The COM encapsulation procedure requires the use of a vacuum laminator and the cells to be able to withstand a short period of air exposure and at least 20 min at elevated temperatures in our case, 150 C . This encapsulation method enabled the cells to pass the IEC 61215 damp heat test and even to retain over 95 of their initial efficiency after 1566 h in a damp heat chamber. Above all, passing the damp heat test for COM encapsulated devices translates to devices fully retaining their initial efficiency for the full duration of the outdoor test gt;10 months . To the best of the authors knowledge, this is one of the longest outdoor stability demonstrations for PSCs published to date. We stress that both encapsulation approaches described in this work are useful for the scientific community as they fulfill different purposes the COM for the realization of prototypes for long term real condition validation and, ultimately, commercialization of perovskite solar cells and the LAB procedure to enable testing and carrying out experiments on perovskite solar cells under noninert conditions

Following the 2nd release of the “Emerging PV reports,” the best achievements in the performance of emerging photovoltaic devices in diverse emerging photovoltaic research subjects are summarized, as reported in peer‐reviewed articles in academic journals since August 2021. Updated graphs, tables, and analyses are provided with several performance parameters, e.g., power conversion efficiency, open‐circuit voltage, short‐circuit current density, fill factor, light utilization efficiency, and stability test energy yield. These parameters are presented as a function of the photovoltaic bandgap energy and the average visible transmittance for each technology and application, and are put into perspective using, e.g., the detailed balance efficiency limit. The 3rd installment of the “Emerging PV reports” extends the scope toward triple junction solar cells.

Daily temperature variations induce phase transitions and lattice strains in halide perovskites, challenging their stability in solar cells. We stabilized the perovskite black phase and improved solar cell performance using the ordered dipolar structure of β-poly(1,1-difluoroethylene) to control perovskite film crystallization and energy alignment. We demonstrated p-i-n perovskite solar cells with a record power conversion efficiency of 24.6% over 18 square millimeters and 23.1% over 1 square centimeter, which retained 96 and 88% of the efficiency after 1000 hours of 1-sun maximum power point tracking at 25° and 75°C, respectively. Devices under rapid thermal cycling between −60° and +80°C showed no sign of fatigue, demonstrating the impact of the ordered dipolar structure on the operational stability of perovskite solar cells.

Photo and charge carrier induced ion migration is a major challenge when utilizing metal halide perovskite semiconductors for optoelectronic applications. For mixed iodide bromide perovskites, the compositional instability due to light or electrical bias induced phase segregation restricts the exploitation of the entire bandgap range. Previous experimental and theoretical work suggests that excited states or charge carriers trigger the process, but the exact mechanism is still under debate. To identify the mechanism and cause of light induced phase segregation phenomena, the full compositional range of methylammonium lead bromide iodide samples are investigated, MAPb BrxI1 x 3 with x 0 1, by simultaneous in situ X ray diffraction XRD and photoluminescence PL spectroscopy during illumination. The quantitative comparison of composition dependent in situ XRD and PL shows that at excitation densities of 1 sun, only the initial stage of photo segregation is rationalized with the previously established thermodynamic models. However, a progression of the phase segregation is observed that is rationalized by considering long lived accumulative photo induced material alterations. It is suggested that additional photo induced defects, possibly halide vacancies and interstitials, need to be considered to fully rationalize light induced phase segregation and anticipate the findings to provide crucial insight for the development of more sophisticated models

Upscaling of hybrid organic-inorganic perovskite solar cells (PSCs) is the most decisive approach towards commercialization of this technology via optimization of scalable manufacturing processes. Here, we report lab-scale slot-die coated “triple cation” Cs0.05FA0.79MA0.16PbBr0.51I2.49 (Cs-MAFA) perovskite solar cells with ~ 16% power conversion efficiency (PCE) measured under 1 sun illumination. This study provides thorough optimization of coating temperature and perovskite ink concentration to obtain favorable morphology and thickness of perovskite thin film. We realized that FACl additive were found to be determining factors to obtain the high performance PSCs. In-situ-GIWAXS measurements were carried out to analyze the perovskite film formation process of perovskite layer with and without FACl additive. This work is important for the development of PSCs modules as well as tandems.

Perovskite-silicon tandem solar cells offer the possibility of overcoming the power conversion efficiency limit of conventional silicon solar cells. Various textured tandem devices have been presented aiming at improved optical performance, but optimizing film growth on surface-textured wafers remains challenging. Here we present perovskite-silicon tandem solar cells with periodic nanotextures that offer various advantages without compromising the material quality of solution-processed perovskite layers. We show a reduction in reflection losses in comparison to planar tandems, with the new devices being less sensitive to deviations from optimum layer thicknesses. The nanotextures also enable a greatly increased fabrication yield from 50% to 95%. Moreover, the open-circuit voltage is improved by 15 mV due to the enhanced optoelectronic properties of the perovskite top cell. Our optically advanced rear reflector with a dielectric buffer layer results in reduced parasitic absorption at near-infrared wavelengths. As a result, we demonstrate a certified power conversion efficiency of 29.80%.

Perovskite–silicon tandem solar cells offer the possibility of overcoming the power conversion efficiency limit of conventional silicon solar cells. Various textured tandem devices have been presented aiming at improved optical performance, but optimizing film growth on surface-textured wafers remains challenging. Here we present perovskite–silicon tandem solar cells with periodic nanotextures that offer various advantages without compromising the material quality of solution-processed perovskite layers. We show a reduction in reflection losses in comparison to planar tandems, with the new devices being less sensitive to deviations from optimum layer thicknesses. The nanotextures also enable a greatly increased fabrication yield from 50% to 95%. Moreover, the open-circuit voltage is improved by 15 mV due to the enhanced optoelectronic properties of the perovskite top cell. Our optically advanced rear reflector with a dielectric buffer layer results in reduced parasitic absorption at near-infrared wavelengths. As a result, we demonstrate a certified power conversion efficiency of 29.80%.

et al., Large datasets are now ubiquitous as technology enables higher-throughput experiments, but rarely can a research field truly benefit from the research data generated due to inconsistent formatting, undocumented storage or improper dissemination. Here we extract all the meaningful device data from peer-reviewed papers on metal-halide perovskite solar cells published so far and make them available in a database. We collect data from over 42,400 photovoltaic devices with up to 100 parameters per device. We then develop open-source and accessible procedures to analyse the data, providing examples of insights that can be gleaned from the analysis of a large dataset. The database, graphics and analysis tools are made available to the community and will continue to evolve as an open-source initiative. This approach of extensively capturing the progress of an entire field, including sorting, interactive exploration and graphical representation of the data, will be applicable to many fields in materials science, engineering and biosciences., Open access funding provided by Helmholtz-Zentrum Berlin für Materialien und Energie GmbH., The core funding of the project has been received from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 787289. We acknowledge the following sources for individual funding. Cambridge India Ramanujan Scholarship, China Scholarship Council, Deutscher Akademischer Austauschdienst (DAAD), EPSRC (grant no. EP/S009213/1), European Union’s Horizon 2020 research and innovation programme (grant no. 764787, EU Project ‘MAESTRO’), (grant no. 756962, ERC Project ‘HYPERION’), (grant no. 764047, EU Project ‘ESPResSo’ and grant no. 850937), GCRF/EPSRC SUNRISE (EP/P032591/1), German Federal Ministry for Education and Research (BMBF), HyPerFORME, NanoMatFutur (grant no. 03XP0091). PEROSEED (ZT-0024), Helmholtz Energy Materials Foundry, The Helmholtz Innovation Laboratory HySPRINT. BMBF (grant nos. 03SF0540, 03SF0557A), HyPerCells graduate school, Helmholtz Association, Helmholtz International Research School (HI-SCORE), the Erasmus programme (CDT-PV, grant no. EP/L01551X/1), the European Union’s Horizon 2020 research and innovation programme (Marie Skłodowska-Curie grant agreement nos. 841386, 795079 and 840751), Royal Society University Research Fellowship (grant no. UF150033). SNaPSHoTs (BMBF), SPARC II, German Research Foundation (DFG, grant no. SPP2196), The National Natural Science Foundation of China (grant no. 51872014), the Recruitment Programme of Global Experts, Fundamental Research Funds for the Central Universities and the ‘111’ project (grant no. B17002), the US Department of Energy’s Office of Energy Efficiency and Renewable Energy under Solar Energy Technologies Office (SETO) agreement no. DE-EE0008551, the Colombia Scientific Programme in the framework of the call Ecosistema Cientifíco (Contract no. FP44842-218-2018), the committee for the development of research (CODI) of the Universidad de Antioquia (grant no. 2017-16000), Spanish MINECO (Severo Ochoa programme, grant no. SEV‐2015‐0522), the Swedish research council (VR, grant no. 2019-05591) and the Swedish Energy Agency (grant no. 2020-005194).

Since the early 2010s, halide perovskites have evolved from an academic curiosity into a promising solar cell technology

To accelerate the materials discovery and development process for a sustainable technology advancement it is imperative to explore and develop combined high throughput material synthesis and analysis workflows. In this work, we investigate a method of combinatorial inkjet printing to tune the composition of the inorganic cesium lead mixed halide perovskite solid solution, CsPb BrxI1 amp; 8722;x 3. The compositional variation is achieved by simultaneous printing of different precursor inks with multiple printheads and controlled by varying the number of droplets printed by each printhead throughout the sample. The droplet placement is optimised through an algorithm that allows maximum mixing of the combined inks. The local compositional homogeneity of thin film samples was investigated as a function of the printing resolution by micrometer resolution X ray fluorescence and synchrotron based grazing incidence wide angle X ray scattering. We show that a combinatorial library of ten compositions between CsPbI3 and CsPbBr2I, printed using the developed algorithm, is locally homogeneous for the optimised printing parameters. An implementation of the algorithm in the high level programming language Python is provided for easy use in other systems

To achieve a monolithic series interconnection of tandem solar cell devices consisting of a perovskite top cell and a CIGSe bottom cell, a two-terminal interconnection scheme is introduced that includes an additional, fourth patterning step, the so-called iso-cut, which separates the window layer stack between the two solar cells. The implementation of this interconnection scheme requires a process development for a total of four structuring steps, which was achieved by systematically varying the laser parameters. Based on a detailed characterization of the individual scribe line properties with respect to their scribe line depth, morphology, electrical functionality, chemical composition and their influence on adjacent and underlying layers, the optimal patterning parameters and suitable process windows were derived for each step, which is a prerequisite for a loss-free monolithic series interconnection in a tandem module.

In contrast to the common conception that the interfacial energy-level alignment is affixed once the interface is formed, we demonstrate that heterojunctions between organic semiconductors and metal-halide perovskites exhibit huge energy-level realignment during photoexcitation. Importantly, the photoinduced level shifts occur in the organic component, including the first molecular layer in direct contact with the perovskite. This is caused by charge-carrier accumulation within the organic semiconductor under illumination and the weak electronic coupling between the junction components.

Within only a few years of systematic research, the unprecedented rise of metal halide perovskites (PSK) as a new class of photovoltaic (PV) absorber materials have considerably changed the PV roadmap when surpassing the efficiencies of inorganic thin film technologies such as Si and CIGSe. Although single junction PSK has reached a certified efficiency of 25.2% and PSK/Si tandem cells have achieved efficiencies over 29 % in small areas [1], the technology does not yet fulfill the requirements for mass production, especially in view of the three targets - manufacturability, sustainability, and stability. The VIPERLAB Consortium (15 partners) has the vision that perovskite-based PV will enable a strong and viable European production base. Therefore, the VIPERLAB project brings together top-ranked, complimentary EU perovskite PV infrastructures, both physical and virtual, to foster perovskite PV development and testing in Europe in order to build a unified access service for EU academic and industrial researchers. The physical and virtual infrastructures provided, by 13 partners of VIPERLAB’s Consortium (Fig. 1), are complementary and cover the whole value chain from material testing, over device processing to reliability testing of the technology. Access to these infrastructures will be provided through a single-entry point [2] for users within the whole European perovskite community, from academia, industry, and other., Proceedings of the 38th European Photovoltaic Solar Energy Conference and Exhibition

Presentation on the "Perovskite Database" Project during online OpenScience conference organized by the GRECO consortium on May 28th 2021.

The upscaling of perovskite solar cells to modules requires the patterning of the layer stack in individual cells that are monolithically interconnected in series. This interconnection scheme is composed of three lines, P1‐P3, which are scribed using a pulsed laser beam. The P3 scribe is intended to isolate the back contact layer of neighboring cells. Previous research has shown that the P3 patterning is often affected by undesired effects such as back contact delamination, flaking, and poor electrical isolation, as laser‐material interactions are not yet fully understood. In this study, the influence of the laser pulse duration on the electrical and compositional properties of P3 scribe lines is investigated. The results show that both ns and ps laser pulses are suitable for P3 patterning, with the ns pulse leading to higher open circuit voltage, higher fill factor, and higher power conversion efficiency. It is found that the longer pulse duration resulted in a larger amount of PbI2 formed within the P3 trench. Next to the P3 line edge, the formation of a thin Br‐rich layer at the perovskite/hole transport layer interface was observed when ns laser pulses were used, which extends up to 12 µm into the active area of the module. Both the formation of PbI2 and a more Br‐rich perovskite layer effectively passivate defects at the edges of the scribe line and block charge carriers in its vicinity. It is concluded that ns laser pulses are preferable for P3 patterning as they promote the formation of beneficial chemical phases, resulting in an improved photovoltaic performance.

Solar cells incorporating metal-halide perovskite (MHP) semiconductors are continuing to break efficiency records for solution-processed solar cell devices. Scaling MHP-based devices to larger area prototypes is a crucial step towards commercialization. This requires the development and optimization of scalable process technology for these devices. Here, we demonstrate a maximum power conversion efficiency (PCE) of 20.83% for slot-die coated gas-quenched small-area methylammonium lead iodide (MAPbI3) devices. Our ink is based on 2-methoxy-ethanol (2-ME) with the strongly coordinating solvent dimethyl-sulfoxide (DMSO) added in small amounts. We found that the amount of DMSO, as well as the age of the precursor solutions, are determining factors in achieving highly efficient and reproducible devices. Through in-depth insight into the film formation process as a function of DMSO content from in-situ X-ray diffraction experiments, we found that just the right amount of DMSO favorably affects thin film growth. Adding 11.77 mol% of DMSO prevents the formation of a crystalline intermediate phase related to MAPbI3 and 2-ME (MAPbI3 -2-ME), reported here for the first time, and inducing the formation of some (DMSO)2MA2Pb3I8 intermediate phase. These results demonstrate that ink composition and process control are critical to enable reproducible large-scale manufacturing of MHP-based devices for commercial applications.

Earlier work by the authors suggested that the formation of molten eutectic regions in Mg-Ca binary alloys caused a discrepancy in ignition temperature when different heating rates are used. This effect was observed for alloys where Ca content is greater than 1 wt%. In this work, the effect of two heating rates (25 °C/min and 45 °C/min) on the ignition resistance of Mg-3Ca is evaluated in terms of oxide growth using X-ray Photoelectron Spectroscopy. It is found that the molten eutectic regions develop a thin oxide scale of ~100 nm rich in Ca at either heating rate. The results prove that under the high heating rate, solid intermetallics are oxidized forming CaO nodules at the metal/oxide interface that eventually contribute to the formation of a thick and non-protective oxide scale in the liquid state.

The European Project GRECO is committed to put into action practices to make scientific work more responsible, specifically those devoted to achieving open science flows where the know-how is shared among different stakeholders representing the quadruple helix of innovation: Government, Industry, Academia and Society. The ultimate objective of GRECO is to provide evidence of these knowledge coalitions and the adoption of a responsible research and innovation global approach facilitates the uptake of socially acceptable innovative solutions. GRECO has developed a model for applying these practices into an early stage research project on the integration of halide perovskites semiconductors (materials for energy conversion) into a novel design of three terminal multi-junction solar devices. On one hand, the Open Science approach for a research that is certainly far away from the market, has implied to accomplish mobilization and mutual learning processes in six different countries, where through a set of dynamics we have achieved a better understanding on the different stakeholders’ perception (including citizens) about emerging materials for energy conversion. In the case of halide perovskites, the question whether a heavy-metal (lead) based semiconductor could be acceptably introduced in consumer products, if safety hazards are sufficiently addressed, is one we like to gather public opinion and perception on. We will explain how we have performed such MML activities and how we have integrated conclusions of such debates into our research activity for making it more responsible, that is, for a better alignment of science funded with Public Funds to the needs, expectations and values of society. And on the other hand, the transition to open science is a process that can be also carried out among representatives of the same stakeholders’ group: researchers. Inevitably there is a need to reach a compromise between the ideal process and the realities of everyday life. Research work is nowadays extremely competitive and researchers have to protect their intellectual property in order to have impact and secure their future funding. Many researchers are put off by possible undesired effects of the implementation of Open Science, such as loss of competitiveness and intellectual property issues. For that reason, GRECO is developing practices that allow a more transparent, reliable and reproducible science without making European researchers less competitive. We will comment on our experience on Open Education, Open Data, Open Proposal, among others and how to utilize these as tools in improving scientific communication for the benefit of government, industry, academic researchers and society.