Sb2S3microbars prepared via the solvothermal method: Precursor sulfur source's effect on structural and optical properties for solar cell applications

Abstract

In this study, antimony sulfide Sb2S3microbarswere successfully fabricated via the solvothermal method using different sulfur sources at 180oC for 14 h. The effects of different sulfur sources including natrium thiosulfate, thiourea, sulfur, and l-cystine on the structural, compositional, and optical properties of the Sb2S3 microbars were inspected using XRD, TEM, XPS, FE-SEM, EDX, UV–vis spectra and Raman scattering. The XRD and Raman spectral studies indicated theSb2S3 microbars’ high purity, crystalline nature, single phase, and orthorhombic structure of in the preferred (1 3 0) orientation. The TEM images showed the formation of well-defined Sb2S3microbars and confirmed the crystallinity. The EDX investigation indicated that the Sb/S atomic ratio was close to2:3, revealing the nearly stoichiometric nature of the Sb2S3 structure. The XPS analysis demonstrated the elemental composition and chemical states. The microbars had absorption coefficients over 104 cm−1and energy gaps between 1.53 and 1.81 eV depending on the precursor sulfur used. The Sb2S3 thin film-based microbars were smooth, compact, and free from holes and cracks with grain sizes of more than 1.5 μm. The highest power conversion efficiency of 3.63% was achieved in the Mo/Sb2S3/CdS/ITO/Ag solar cell structure, with open-circuit voltage Voc = 465 mV, short-circuit current density Jsc = 12.83 mA/cm2, and a fill factor FF = 60.9%when thiourea was used as the sulfur source.