Antimony sulfide selenide thin film solar cells prepared from thermal evaporation sources produced via chemical reactions

Abstract

Continued research during the past twenty years has contributed toward an increase in the conversion efficiency of antimony sulfide selenide thin film solar cells above 10%. Hence, new methodologies to open-up this research are relevant. Here, antimony sulfide selenide thin film solar cells were prepared by thermal evaporation from Sb2SxSe3-x sources obtained via an in-situ reaction of SbCl3, Se and Sb2S3 for a desired mole-ratio. A thin film (175 nm) of Sb2S2.1Se0.9 prepared this way with a bandgap (Eg) of 1.67 eV and photoconductivity, 10 −6 Ω– 1 cm– 1. Its solar cell, SnO2:F (FTO)/CdS(100 nm)/Sb2S2.1Se0.9 (175 nm)/C–Ag, has an open circuit voltage (Voc) of 0.514 V, short circuit current density (Jsc) of 11.78 mA cm – 2, and a solar-to-electric energy conversion efficiency (η) of 2.36%. Powder mixture with increased Se-content in the SbCl3 + Se + Sb2S3 mixture was produced in a tubular oven at 450 °C, and used as a source. A thin film of Sb2S0.7Se2.3 (190 nm) produced this way has an Eg of 1.29 eV and photoconductivity, 7x10 – 5 Ω – 1 cm – 1. For its solar cell, FTO/CdS(100 nm)/Sb2S0.7Se2.3 (190 nm)/C–Ag, Voc is 0.455 V; Jsc, 20.3 mA cm – 2 and η, 4.52%. This method of preparing Sb2SxSe3-x thin film solar cells of varying compositions offers versatility in vacuum thermal evaporation from sources prepared from laboratory grade reagents. Perspectives for further work to improve the solar cell efficiency are presented.