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Institute: search.filters.UBSInstitut.Zentrum für Sonnenenergie- und Wasserstoff-Forschung Baden-Württemberg (ZSW)Subject: search.filters.subject.333.7

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    Coordination chemistry as a universal strategy for a controlled perovskite crystallization
    (2023) Zuo, Weiwei; Byranvand, Mahdi Malekshahi; Kodalle, Tim; Zohdi, Mohammadreza; Lim, Jaekeun; Carlsen, Brian; Magorian Friedlmeier, Theresa; Kot, Małgorzata; Das, Chittaranjan; Flege, Jan Ingo; Zong, Wansheng; Abate, Antonio; Sutter‐Fella, Carolin M.; Li, Meng; Saliba, Michael
    The most efficient and stable perovskite solar cells (PSCs) are made from a complex mixture of precursors. Typically, to then form a thin film, an extreme oversaturation of the perovskite precursor is initiated to trigger nucleation sites, e.g., by vacuum, an airstream, or a so-called antisolvent. Unfortunately, most oversaturation triggers do not expel the lingering (and highly coordinating) dimethyl sulfoxide (DMSO), which is used as a precursor solvent, from the thin films; this detrimentally affects long-term stability. In this work, (the green) dimethyl sulfide (DMS) is introduced as a novel nucleation trigger for perovskite films combining, uniquely, high coordination and high vapor pressure. This gives DMS a universal scope: DMS replaces other solvents by coordinating more strongly and removes itself once the film formation is finished. To demonstrate this novel coordination chemistry approach, MAPbI3 PSCs are processed, typically dissolved in hard-to-remove (and green) DMSO achieving 21.6% efficiency, among the highest reported efficiencies for this system. To confirm the universality of the strategy, DMS is tested for FAPbI3 as another composition, which shows higher efficiency of 23.5% compared to 20.9% for a device fabricated with chlorobenzene. This work provides a universal strategy to control perovskite crystallization using coordination chemistry, heralding the revival of perovskite compositions with pure DMSO.
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    ItemOpen Access
    Irradiation-dependent topology optimization of metallization grid patterns and variation of contact layer thickness used for latitude-based yield gain of thin-film solar modules
    (2022) Zinßer, Mario; Braun, Benedikt; Helder, Tim; Magorian Friedlmeier, Theresa; Pieters, Bart; Heinlein, Alexander; Denk, Martin; Göddeke, Dominik; Powalla, Michael
    We show that the concept of topology optimization for metallization grid patterns of thin-film solar devices can be applied to monolithically integrated solar cells. Different irradiation intensities favor different topological grid designs as well as a different thickness of the transparent conductive oxide (TCO) layer. For standard laboratory efficiency determination, an irradiation power of 1000W/m2is generally applied. However, this power rarely occurs for real-world solar modules operating at mid-latitude locations. Therefore, contact layer thicknesses and also lateral grid patterns should be optimized for lower irradiation intensities. This results in material production savings for the grid and TCO layer of up to 50 % and simultaneously a significant gain in yield of over 1%for regions with a low annual mean irradiation.
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    Integrated Policy Package Assessment (IPPA) : a problem-oriented research approach for sustainability transformations
    (2022) Scheer, Dirk; Schmidt, Maike; Dreyer, Marion; Schmieder, Lisa; Arnold, Annika
    In this paper, we present the Integrated Policy Package Assessment (IPPA) approach and relate IPPA to three substantial concepts of problem-oriented research concerned with societal transformations: technology assessment (TA), sustainability research (SR), and responsible research and innovation (RRI). The IPPA approach provides (political) decision-makers with transformation and orientation knowledge via a four-step process of (1) design, (2) analysis, (3) evaluation, and (4) discourse of a policy package assessment. It is illustrated with a case study of urban passenger transport. As an integrated approach, IPPA has substantial ties to TA, SR, and RRI. It connects with TA in fundamental ways, since it combines the field of TA with the field of regulatory assessment based on consequence analysis. Connectable to the field of SR, IPPA addresses deliberation processes and sustainable pathway identification based on multi-criteria assessment. In addition, akin to the area of RRI, IPPA shows cross-cutting axes with regards to social resonance assessment and stakeholder evaluation with a focus on multi-actor responsibilities. In this contribution, we link evidence-based impact assessment with transformation pathway mechanisms and corresponding policy packages, backed by stakeholder-based responsible innovation feedback loops. This enhances the ex-ante analysis of policy packages regarding their intended as well as unintended consequences.
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    All-inorganic CsPbI2Br perovskite solar cells with thermal stability at 250 °C and moisture-resilience via polymeric protection layers
    (2025) Roy, Rajarshi; Byranvand, Mahdi Malekshahi; Zohdi, Mohamed Reza; Magorian Friedlmeier, Theresa; Das, Chittaranjan; Hempel, Wolfram; Zuo, Weiwei; Kedia, Mayank; Rendon, Jose Jeronimo; Boehringer, Stephan; Hailegnanw, Bekele; Vorochta, Michael; Mehl, Sascha; Rai, Monika; Kulkarni, Ashish; Mathur, Sanjay; Saliba, Michael
    All-inorganic perovskites, such as CsPbI2Br, have emerged as promising compositions due to their enhanced thermal stability. However, they face significant challenges due to their susceptibility to humidity. In this work, CsPbI2Br perovskite is treated with poly(3-hexylthiophen-2,5-diyl) (P3HT) during the crystallization resulting in significant stability improvements against thermal, moisture and steady-state operation stressors. The perovskite solar cell retains ∼90% of the initial efficiency under relative humidity (RH) at ∼60% for 30 min, which is among the most stable all-inorganic perovskite devices to date under such harsh conditions. Furthermore, the P3HT treatment ensures high thermal stress tolerance at 250 °C for over 5 h. In addition to the stability enhancements, the champion P3HT-treated device shows a higher power conversion efficiency (PCE) of 13.5% compared to 12.7% (reference) with the stabilized power output (SPO) for 300 s. In addition, the P3HT-protected perovskite layer in ambient conditions shows ∼75% of the initial efficiency compared to the unprotected devices with ∼28% of their initial efficiency after 7 days of shelf life.