Kesterite Cu 2 ZnSnS 4 thin films synthesized utilizing electrodeposition: Influence of metal doping on the properties

Abstract

In the present study, kesterite films were synthesized by sulfurization of co-electrodeposited Cu2ZnSnS4 (CZTS) precursor, focusing on the effect of different metals (Li, Na, Sb, and Cr) on the CZTS thin films' properties. The structural, morphological, electrical and optical properties of the films were investigated. We demonstrated the deposition of four different metals using spin-coating on co-electrodeposited thin films. X-ray diffraction (XRD) confirmed the kieserite phase with major intense peaks corresponding to the (112), (200), (312) and (332) planes with improvement in crystallinity after doping. Raman spectroscopy indicated the presence of a pure kesterite phase with a minor amount of impurities in the Na-doped CZTS thin film. FE-SEM analyses showed smooth, compact, and uniform surface morphology with fewer holes and cracks and well-defined boundaries between the submicron particles and adherent layer cross section. An energy gap absorption edge ranging from 1.56 eV to 1.71 eV was calculated from the absorption measurements, while improvements in the energy gab were observed depending on the doping metal. The absorption coefficient was higher than 104 cm−1 in the visible spectrum of light. The performance of the solar cell with a device configuration of Glass/Mo/CZTS/CdS/i-ZnO/ZnO: Al/Ag under simulated AM 1.5 was reported. The presence of different dopants increased the average efficiency from 1.74% ± 0.4 to 3.47% ± 0.3. Upon Na doping, solar cell device demonstrated as high-performance efficiency as 3.47%, featuring open-circuit voltage Voc = 343 mV, short-circuit current density Jsc =12.55 mA/cm2, and a fill factor FF = 69.1.