EXAFS Study of the Local Order in Cu2ZnSn(SxSe1–x)4 Alloys

Abstract

Local structure in Cu2ZnSn(SxSe1–x)4 alloys is studied by the extended X‐ray absorption fine structure (EXAFS) method. K edge absorption spectra of four elements: Cu, Zn, Sn, and Se have been measured. The EXAFS analysis of the nearest neighbor shell is performed using simultaneous fitting of the data for all four K edges. This provides value of structural parameters in the most consistent way. The cation–anion interatomic distances exhibit the bimodal behavior, i.e., the Me–S and Me–Se distances (Me = Cu, Zn, and Sn) are practically constant over the whole composition range of Cu2ZnSn(SxSe1–x)4 alloys. They are compared to the X‐ray diffraction (XRD) values for these alloys. The analysis of the EXAFS Debye‐Waller factors indicates differences in the static disorder around different cations with the lowest disorder observed in the first coordination shell of Sn atoms.