Growth and characterization of ZnSxSe1-x thin films deposited by spray pyrolysis

In this work, zinc sulphoselenide ZnSxSe1-x; (0.0 ≤ x ≤ 1.0) thin films were grown on glass substrates using a computerized chemical spray pyrolysis. The mechanism of growth and the structural, morphological, compositional, optical and electrical properties were studied. An X-ray diffraction study confirmed that the polycrystalline ZnSxSe1-x thin films had a cubic zinc blende structure with a preferential 〈111〉 orientation. The shift in the peak <111> direction towards higher 2θ values with increasing sulfur concentration confirmed the formation of a solid solution. The crystallite size was observed to be in the range 18-28 nm. Using energy dispersive X-ray spectroscopy, the formation of nearly stoichiometric ZnSxSe1-x thin films was confirmed. The optical band gap increased from 2.84 eV to 3.57 eV when the composition of the ZnSxSe1-x was changed. The thin films were found to be semiconducting in nature. The observed tunable optical and electrical properties of the ZnSxSe1-x thin films suggest that they can be used for a wide range of optoelectronic applications.