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The certified power conversion efficiency of state-of-the-art organic–inorganic hybrid perovskite solar cells has surpassed 25%, showing promising potential for commercialization. Compared with vol...

This review focuses on the advancements in stability of perovskite solar cells under stress from ambient moisture, high temperatures, and UV light exposure. Moisture stability has been improved by utilizing several polymeric encapsulation methods, moisture-resistant hole transport layers (HTLs), CF4 plasma treatments, and perovskite grain crosslinking. Fluorinated encapsulation methods have proven especially successful, producing cells that maintained their PCE after 75 days at 50% RH and 5 mW cm−2 of UV radiation. Temperature destabilization has been hypothesized to occur as a result of perovskite phase transitions and the HTL dopant migration to the mesoporous TiO2 surface. Temperature-sensitive perovskites have been stabilized by tuning the Goldschmidt tolerance factor and introducing thermally resistant HTLs embedded in a polymeric matrix with polycarbonate acting as an effective thermal insulating matrix. UV light instabilities have also been shown to occur due to the photocatalysis of TiO2 and the TiO2 perovskite interface. The introduction of a Sb2S3 buffer or CsBr clusters as interface modifiers can stabilize the interface of TiO2 perovskite. Herein, we aim at highlighting the main processes that prevent perovskite degradation using polymers and interfacial modifiers.

One of the organic components in the perovskite photo-absorber, the methylammonium cation, has been suggested to be a roadblock to the long-term operation of organic–inorganic hybrid perovskite-based solar cells. In this work we systematically explore the crystallographic and optical properties of the compositional space of mixed cation and mixed halide lead perovskites, where formamidinium (FA+) is gradually replaced by cesium (Cs+), and iodide (I−) is substituted by bromide (Br−), i.e., CsyFA1−yPb(BrxI1−x)3. Higher tolerance factors lead to more cubic structures, whereas lower tolerance factors lead to more orthorhombic structures. We find that while some correlation exists between the tolerance factor and structure, the tolerance factor does not provide a holistic understanding of whether or not a perovskite structure will fully form. By screening 26 solar cells with different compositions, our results show that Cs1/6FA5/6PbI3 delivers the highest efficiency and long-term stability among the I-rich compositions. This work sheds light on the fundamental structure–property relationships in the CsyFA1−yPb(BrxI1−x)3 compositional space, providing vital insight to the design of durable perovskite materials. Our approach provides a library of structural and optoelectronic information for this compositional space.

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).

Organic-inorganic halide perovskites have been identified as favorable candidates for the next generation of photovoltaics. Adding alkali metal halides to perovskite films has been shown to be a viable option to improve the perovskite film quality and to modulate their fundamental properties. In this work, we perform optical and electron-beam based characterizations of mixed Sn/Pb based perovskite films to investigate the effect of the addition of the alkaline metal halide SrI2. By analyzing structural (X-ray diffraction), morphological (Scanning Electron Microscopy), optical (photoluminescence), and chemical properties (X-ray photoelectron spectroscopy), we show a complex interplay of effects upon addition of Sr2+ into the perovskite solution. Low concentrations of Sr2+ increases lattice strain, which hints at incorporation of the additive into the perovskite lattice and improves the film optoelectronic properties. As the additive concentration increases beyond 0.5 mol %, microstrain decreases. At concentrations >0.5 mol %, Sr2+ induces significant reduction of the average domain size, which impacts both structural and optical properties of the perovskite film.