Regensburg 2025 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

KFM: Fachverband Kristalline Festkörper und deren Mikrostruktur

KFM 2: Perovskite and Photovoltaics I (joint session HL/KFM)

KFM 2.1: Talk

Monday, March 17, 2025, 09:30–09:45, H13

Oxygen-Mediated (0D) Cs4PbX6 Formation during Open-Air Thermal Processing Improves Inorganic Perovskite Solar Cell Performance — Rafikul Ali Saha¹, •Wei-Hsun Chiu², Giedrius Degutis¹, Peng Chen³, Matthias Filez⁴, Eduardo Solano⁵, Nikolai Orlov⁶, Francesco De Angelis⁷, Carlo Meneghini⁷, Christophe Detavernier⁴, Sawanta S. Mali⁸, Minh Tam Hoang², Yang Yang², Erik C. Garnett⁹, Lianzhou Wang³, Hongxia Wang², Maarten B. J. Roeffaers¹, and Julian A. Steele³ — ¹KU Leuven, Belgium — ²Queensland University of Technology, Brisbane, Australia — ³The University of Queensland, Brisbane, Australia — ⁴Ghent University, Belgium — ⁵ALBA synchrotron, Barcelona, Spain — ⁶AMOLF, Amsterdam, The Netherlands — ⁷Roma Tre University, Rome, Italy — ⁸Chonnam National University, Gwangju, South Korea — ⁹University of Amsterdam, The Netherlands

We highlight the beneficial role of ambient oxygen during the open-air thermal processing of metastable γ-CsPbI3-based perovskite thin films and devices. Physiochemical-sensitive probes elucidate oxygen intercalation and the formation of Pb-O bonds in the perovskite, entering via iodine vacancies at the surface, creating superoxide (O2-) through electron transfer reactions, which drives the formation of a zero-dimensional (0D) Cs4PbI6 protective capping layer during annealing (>330°C). Applied to γ-CsPbI2Br perovskite solar cells, it boosts the operational stability and photo-conversion efficiency of champion devices from 12.7% to 15.4% when annealed in dry air.

Keywords: inorganic metal halide perovskite; phase stability; ambient oxygen; CsPb(I,Br)3; solar cells