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In situ Near‐Ambient Pressure X‐ray Photoelectron Spectroscopy Reveals the Influence of Photon Flux and Water on the Stability of Halide Perovskite
Author(s) -
Kot M.,
Kegelmann L.,
Köbler H.,
Vorokhta M.,
Escudero C.,
Kúš P.,
Šmíd B.,
Tallarida M.,
Albrecht S.,
Abate A.,
Matolínová I.,
Schmeißer D.,
Flege J. I.
Publication year - 2020
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.202001527
Subject(s) - x ray photoelectron spectroscopy , perovskite (structure) , hysteresis , halide , materials science , analytical chemistry (journal) , ambient pressure , spectroscopy , flux (metallurgy) , optoelectronics , chemical physics , chemical engineering , chemistry , inorganic chemistry , condensed matter physics , physics , crystallography , thermodynamics , chromatography , quantum mechanics , engineering , metallurgy
For several years, scientists have been trying to understand the mechanisms that reduce the long‐term stability of perovskite solar cells. In this work, we examined the effect of water and photon flux on the stability of CH 3 NH 3 PbI 3 perovskite films and solar cells using in situ near‐ambient pressure X‐ray photoelectron spectroscopy (NAP‐XPS), field emission scanning electron microscopy (FESEM), and current density–voltage ( J – V ) characterization. The used amount of water vapor (up to 1 mbar) had a negligible impact on the perovskite film. The higher the photon flux, the more prominent were the changes in the NAP‐XPS and FESEM data; also, a faster decline in power conversion efficiency (PCE) and a more substantial hysteresis in the J ‐ V characteristics were observed. Based on our results, it can be concluded that the PCE decrease originates from the creation of Frenkel pair defects in the perovskite film under illumination. The stronger the illumination, the higher the number of Frenkel defects, leading to a faster PCE decline and more substantial hysteresis in the J ‐ V sweeps.