Effect of Thiourea Concentration on Structural, Optical and Electrical Properties of Cu2ZnSnS4 Thin Films Prepared by using Spray Pyrolysis
Biplav Dahal *
Department of Physics, Patan Multiple Campus, Patan Dhoka, Lalitpur, Nepal
Leela Pradhan Joshi
Department of Physics, Amrit Science Campus, Lainchour, Kathmandu, Nepal
Satyendra N. Pandey
Department of Physics, Motilal Nehru National Institute of Technology, Allahabad -211 004, India
Shankar Prasad Shrestha *
Department of Physics, Patan Multiple Campus, Patan Dhoka, Lalitpur, Nepal
*Author to whom correspondence should be addressed.
Abstract
Thin films of Cu2ZnSnS4 (CZTS) with different molar concentrations of thiourea were prepared on glass substrates using spray pyrolysis technique. The structural, optical and electrical properties of the CZTS thin films were investigated using X-ray diffraction (XRD), UV-vis spectroscopy and sheet resistance measurement respectively. The XRD analysis demonstrated the polycrystalline nature of the CZTS. We observed better crystallanity in CZTS film prepared with thiourea concentration of 0.20 M and optical band gap value at this concentration was observed to be 1.60 eV. The optical study showed that band gap increased with an increase in thiourea concentration. The sheet resistance of the sample prepared with 0.20 M concentration of thiourea was 10.73 Kohm/sq.
Keywords: CZTS thin films, spray pyrolysis, X-ray diffraction, thiourea concentration