SPLTRAK Abstract Submission
Evaluating Intrinsic Defects Across CIGS Absorber via X-ray Absorption Near Edge Structures
Srisuda Rojsatien1, Tara Nietzold1, Niranjana Kumar1, Barry Lai2, Jeff Bailey3, Arun Mannodi-Kanakkithodi3,4, Maria K. Y. Chan3, Mariana Bertoni1
1Arizona State University, Tempe, AZ, United States
/2Argonne National Laboratory, Argonne, IL, United States
/3MiaSolé Hi-Tech Corp., Santa Clara, CA, United States
/4Purdue University, West Lafayette, IN, United States

X-ray Absorption Near Edge Structures (XANES) is a powerful tool to unravel chemical environment as it is sensitive to oxidation state and small structural variations. In this work, we measured XANES spectra and simulated structures to fit the Se local structures, including intrinsic defects around Se atoms, inside the absorber layer of Cu(In,Ga)Se2 (CIGS) solar cells. This work reveals for the first time the distributions of point defects in the absorber, across the Mo and CdS interfaces, validating the presence of selenium vacancies (VSe) and copper vacancies (VCu) proposed by multiple authors but also suggesting that there are more clusters of VSe and VCu on the CdS side and more VCu clusters on the Mo side.