Chemically deposited ZnS thin films: application as substrate for chemically deposited Bi2S3, CuxS and PbS thin films

Abstract

Chemical deposition of good quality ZnS thin films from aqueous solutions containing zinc sulphate, NH₃/NH₄Cl buffer (pH 10), triethanolamine and thioacetamide is described. It is shown that the presence of these films on glass substrates offers various advantages in the case of chemically deposited metal sulphide thin films: (i) improved adhesion of Bi₂S₃ thin films, which is vital for growing films of thickness >0.2 mu m for semiconductor applications and in metal sulphide thin film (MSTF) photography based on photoaccelerated chemical deposition; (ii) improved adhesion of Cu_xS films, offering the choice of different shades of colours for the same integrated transmittance in the visible region of approximately 20% in solar control coatings and the possibility of multiple-dip deposition of Cu_xS films to enhance the film thickness, enabling the realization of solar absorptance of approximately 90%; and (iii) reduced reflectance in the visible light which can reduce the glare from PbS solar control coatings and improve the solar absorptance in thicker PbS coatings and offer better contrast in MSTF photography.