Preparation of In2S3 Thin Film Using Thermal Evaporator Technique

Abstract

In2S3 thin film of 689 nm thickness was successfully deposited on a glass substrates using sulfurate method under vacuum in a sealed tube of amorphous indium thin film. Furthermore thin film is pre-deposited on glass with thermal evaporation method. A study on the effect of the annealing temperature have been done for (200, 300 and 350)° C. Thin films were structurally characterized by X-ray diffraction and surface roughness scanned test via ISO step height analysis. The optical transmission and absorption measurements were considered. It has been found that the optical direct band gap varied from (2.55- 3)eV with different annealing temperatures (200 – 350)o C . X-ray diffraction results shows that the films have poly-crystalline structure on the glass substrates. Roughness analysis images illustrate a quite smooth and uniform surface with a low surface roughness. These results can be explained as non-stoichiometric composition of indium sulphide which may result in different band gaps. Hence, a specific stoichiometric composition which results in the highest band gap is desirable to achieve high efficiency for InxSy-CIGS solar cell