Spin-Coated Uniform Sb2S3 Thin Films for Photovoltaic Applications by Solvent Engineering

Abstract

Spin-coated Sb2S3 inorganic semiconductor thin films are a good substitute for conventional Sb2S3 absorbers prepared by chemical bath deposition due to the ability to control antimony oxide defects and the simplicity of the spin-coating process. However, precise control of the morphology of the Sb2S3 thin films is crucial for optimizing the photovoltaic properties of inorganic-organic hybrid solar cells. In this work, we attempt to fabricate high-purity Sb2S3 thin films with a uniform morphology via solvent engineering. The compositional ratio and concentration of the precursor solutions containing SbCl3 and thiourea are varied, and the chemical composition and morphology of the spin-coated Sb2S3 thin films are investigated. The morphology of the Sb2S3 thin films is predominantly determined by the morphology of the precursor films, which are formed by a complex reaction between SbCl3 and thiourea after the spin-coating process. Controlling the complex reaction enables the fabrication of uniform Sb2S3 thin films using the spin-coating process. In order to evaluate the photovoltaic properties of the spin-coated Sb2S3 thin films, planar Sb2S3 solar cells comprised of Au/Poly-3-hexylthiophene/Sb2S3/bl-TiO2/FTO are fabricated, and the current-voltage characteristics of these solar cells are investigated.