Rapid Chemical Bath Deposition and Optical Property of CuS Films Using Sodium Ethylenediamine Tetraacetate as Chelating Agent

CuS films were fabricated by a chemical bath deposition process in an aqueous solution of cupric acetate, thiourea, and different contents of sodium ethylenediamine tetraacetate (EDTA-2Na) at 50ºC. The films were characterized by X-ray diffraction, atomic force microscopy, ultraviolet-visible spectrophotometry and photoluminescence spectrophotometry. The effects of EDTA-2Na content and deposition time on the deposition rate, thickness, transmittance, band gap energy and photoluminescence of the films were investigated. The films were fast deposited with this method. Molar ratio of EDTA-2Na/Cu2+=1.0 led to fastest deposition. The band gap energy of the films is in the range of 2.59−2.92 eV, decreasing with increasing deposition time. The films showed broad emission centered at ~443 nm.