@inproceedings{fc2d5b3c3bca4e2d9e855cc305d7679f,
title = "Insight into Metastable Defects in Flexible \text{Cu}(\text{In}_{1-x}\text{Ga}_{x})\text{Se}_{2} Modules via X-ray Microscopy",
abstract = "The origin of metastability in \text{Cu}(\text{In}_{1-x}\text{Ga}_{x})\text{Se}_{2} solar cells has long be a topic of study and debate. The drop in device performance after light soaking has been attributed to changes in the VSe-VCu defect pair and to the electromigration of Cu. In this work, we use a suite of X-ray microscopy tools to study the nanoscale distribution of Cu and Se in industrially-relevant CIGS modules on stainless steel before and after accelerated stress testing from dark heat and light soaking. Changes in chemical inhomogeneity are studied through nano-scale X-ray fluorescence and correlated to electrical performance through Xray beam induced current and voltage. We observe no meaningful variation in the Cu distribution before and after light soaking but a sensible difference in the Se distribution. Average XBIC values at the nano-scale trend directly with changes in full device J_{\text{sc}} both of which see a reduction after light soaking. We note that low performing areas of XBIC in both the initial and dark heat samples perform significantly worse after light soaking when compared to changes in the good performing areas.",
keywords = "CIGS, X-ray beam induced current, X-ray fluorescence, dark heat, defects, light soaking, selenization, {Cu}({In}_{1-x}{Ga}_{x})\text{Se}_{2}",
author = "Tara Nietzold and Stuckelberger, {Michael E.} and Trumann Walker and Jeff Bailey and Dmitry Poplavskyy and Rouin Farshchi and Barry Lai and Bertoni, {Mariana I.}",
note = "Funding Information: ACKNOWLEDGMENTS We acknowledge funding from the U.S. Department of Energy under contract DE-EE0008163 and from Deutsches Elektronen-Synchrotron (DESY). Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect those of NSF or DOE. Publisher Copyright: {\textcopyright} 2020 IEEE.; 47th IEEE Photovoltaic Specialists Conference, PVSC 2020 ; Conference date: 15-06-2020 Through 21-08-2020",
year = "2020",
month = jun,
day = "14",
doi = "10.1109/PVSC45281.2020.9300377",
language = "English (US)",
series = "Conference Record of the IEEE Photovoltaic Specialists Conference",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
pages = "1375--1379",
booktitle = "2020 47th IEEE Photovoltaic Specialists Conference, PVSC 2020",
}