Chemical bath deposition of Sb₂S₃ thin films using the mixing solution of SbCl₃ and sodium citrate as a novel Sb source for assembling efficient solar cells

In this work, Sb2S3 thin films were successfully prepared by chemical bath deposition (CBD) using the mixing solution of SbCl3 and sodium citrate as a novel Sb source. The influence of the solution chemical composition, deposition process parameters, CdS thin film microstructure on the properties of Sb2S3 thin films and the photovoltaic performance of the corresponding solar cells was systematically investigated. The CBD growth mechanism of Sb2S3 thin films was explored from the thickness increase and the molar ratio evaluation of Sb-O : Sb-S/O. The result revealed that the CBD growth process of Sb2S3 thin films was dominated by the nanoparticle formation-adsorption pathway. When the SbCl3 concentration was 120 mM, the molar ratio of SbCl3 : sodium citrate : Na2S2O3 : thioacetamide was 1 : 2.3 : 1.5 : 0.5, the growth solution volume was 48 mL, the growth temperature and time were 90 degrees C and 6 h, and the Sb2S3 solar cell with the architecture of FTO/CdS/Sb2S3/spiro-OMeTAD:TMT-TTF/Au achieved a power conversion efficiency (PCE) of 7.63%, along with an open-circuit voltage of 0.78 V, a short-circuit photocurrent density of 16.89 mA cm(-2), and a fill factor of 0.58. The PCE of 7.63% was relatively high in Sb2S3 solar cells and the application for the mixing solution of SbCl3 and sodium citrate as the Sb source can open up a broad space for the preparation of antimony chalcogenide thin films.