Growth and Characterization of ZnSxSe1 x Thin Films for Photoelectrochemical Solar Cell Applications

Abstract

From the literature survey, it was found that various physical and chemical techniques are available to synthesize binary ZnS and ZnSe as well as ternary ZnSxSe1-x thin films. The properties of thin films as well as their usefulness in various fields strongly depend on the technique used for deposition. Spray pyrolysis is one of the attractive chemical techniques used to synthesize uniform binary, ternary and quaternary chalcogenides thin films of good quality. It offers some remarkable advantages compared with the other techniques. It is simple to carry out, facilitates doping, is affordable, can be carried out at moderate temperatures (100-500°C) and is of short duration. In the spray process, we can control the film thickness, surface morphology and composition very easily. Because of its simplicity and number of benefits, the computerized chemical spray pyrolysis technique was used in the present research work. newlineThe present research work is broadly divided into: (A) growth of high quality and uniform ZnS, ZnSe and ZnSxSe1-x (0.0 lt x lt 1.0) thin films using the chemical spray pyrolysis technique, (B) Physico-chemical and PEC characterization of ZnSxSe1-x (0.0 and#8804; x and#8804; 1.0) thin films, (C) doping of ZnS0.2Se0.8 thin films with a trivalent iron (Fe) impurity and (D) Physico-chemical and PEC characterization of Fedoped ZnS0.2Se0.8 thin films. newlineZnSxSe1-x (0.0 and#8804; x and#8804; 1.0) ternary thin films with good uniformity were grown on ultrasonically cleaned amorphous glass (soda lime glass type) and fluorine-doped tin oxide (FTO) coated conducting glass (sheet resistance in the range 8-10 and#937;-cm 2) substrates. The precursor zinc chloride was used as the source of Zn2+ ions, while thiourea and selenourea were used as the source of S2- and Se2- ions, respectively. Solvents such as freshly prepared double distilled water and isopropyl alcohol were used. The various important preparative parameters, including the deposition temperature, concentration and amount of spray solution, and spray rate were optimized in order to obtain good qua