Optical and photovoltaic properties of vacuum-evaporated CZTSe, CAZTSe, and AZTSe thin films: a comparative study

摘要

In this work, we analyzed the structural, morphological, optical, and electrical properties of vacuum-evaporated Cu_2ZnSnS_4 (CZTSe), CuAgZnSnS_4 (CAZTSe), and Ag_2ZnSnS_4 (AZTSe) thin films. The structural analysis confirms the presence of tetragonal-structured CZTSe and showed peak shift toward the lower angle for CAZTSe and AZTSe films. Raman spectra indicate the presence of SnSe (at 140 cm~(-1)), ZnSe (at 255 cm~(-1)), and CuSe (at 280 cm~(-1)) as secondary phases. The EDS analysis is evidenced for the presence of Cu, Ag, Zn, Sn, and Se signals with Zn- and Sn-rich condition. SEM images picturized the spherical-shaped particles rich with irregular-shaped particles. Among the films, CAZTSe showed good optical absorption behavior in the visible region. CZTSe shows p-type conductivity, while the CAZTSe and AZTSe films show n-type conductivity as identified by Hall Effect analysis. The CAZTSe film exhibited higher mobility which is good for photovoltaic applications. FTO/CZTSe/AZTSe/Ag and FTO/CZTSe/CAZTSe/Ag solar cells were fabricated and its Photocon-version Efficiency (PCE) is studied.