Modification of optoelectronic properties of sprayed CZTS thin films through spray rate variation

Abstract

Effect of spray rate on structural, optical and electrical properties of spray pyrolysed Cu2ZnSnS4 (CZTS) thin films was investigated. We deposited films by varying spray rate from 2 ml/min to 10 ml/min in steps of 2 ml/min. For very low and high spray rates presence of secondary phases could be observed while for the films prepared at a spray rate of 6 ml/min were devoid of secondary phases. As spray rate increases band gap decreased. Samples prepared at 6 ml/min had optimum band gap of 1.5 eV. All the samples were observed to be p-type. Resistivity values increased steadily up to 6 ml/min and then slightly decreased. From the present work, CZTS films prepared at a spray rate of 6 ml/min is found to be ideal for absorber layer in solar cell.