Solar Energy Materials and Solar Cells 26 (1992) 117-136 North-Holland Solar Energy Materials and Solar Cells Studies on new chemically deposited photoconducting antimony trisulphide thin films O. Savadogo 1 and K.C. Mandal Ddpartement de Mdtallurgie et de Gdnie des Mat&iaux, Ecole Polytechnique de Montrdal, C.P. 6079, Succ. A, Montrdal, Qudbec, Canada H3C 3A 7 Received 3 August 1991; in revised form 15 October 1991 A new room temperature chemical deposition technique has been developed to deposit semiconducting antimony trisulphide thin films on conducting and ordinary glass substrates. The method is based on aqueous ammonia bath containing potassium antimonyl tartarate (PAT), triethanolamine (TEA) and thioacetamide (TAM). It has been found that the proper control of deposition bath compositions significantly influences the quality and the thickness of the Sb2S 3 films. Moreover, addition of a small amount (10 s M) of silicotungstic acid (STA) in the deposition bath enhanced the rate of deposition and improves significantly the photoactivity of the films. The deposited films were characterized by X-ray, SEM and neutronic activation analysis. The effect of the annealing and STA on the change of the optical bandgap (Eg) of the films was determined at 300 K. The influence of the STA on the resistivity, carrier concentra- tions and mobility of the films was determined by the resistivity and Hall effect measurements on the annealed samples. A very small ( -~ 5%) change in the electrical resistivity has been observed for the films in which STA is incorporated. X-ray photoelectron spectroscopic (XPS) studies were carried out to determine the surface and the bulk compositions of the films. The photoconductivity studies revealed that the deposited films were highly photoconducting in nature. 1. Introduction Recently, there has been considerable interests for developing new polycrys- talline thin film semiconductors using various techniques [1-5]. Among them, chemical deposition method has found out a special significance. Because this method is proved to be the least expensive, low temperature method and a non-pollutant one. Moreover, the quality of the films regarding the electrical and optical properties can be altered easily by incorporating suitable dopant materials in the chemical bath. So, no sophisticated technology such as photolithography, diffusion, ion implantation, etc., are required to achieve a material with desired properties. This method is also very suitable for making films of large area and of any configurations. Among the metal sulphides, antimony trisulphide finds special applications in target material for television cameras [6], microwave devices [7], switching devices [8] and various opto-electronic devices [9-11]. In all these cases, 1 To whom correspondence should be addressed. 0927-0248/92/$05.00 © 1992 - Elsevier Science Publishers B.V. All rights reserved