VARIATIONOF CHARACTERISTIC PROPERTIES OF Cu2ZSnS4 DEPOSITED BY ELECTRODEPOSITION LAYERING OF CZT METHOD COUPLEDWITH CHEMICAL BATH IN Na2S SOLUTION TECHNIQUEWTH ANNEALING TEMPERATURE

Abstract

Cu2ZSnS4 (CZTS) solar technology is considered as a viable replacement to copper indium gallium selenide (CIGS) solar technology. Though CIGS technology has achieved high efficiency, 20%, it is faced with problems of material scarcity and toxicity. Therefore, CZTS which contains earth abundant and nontoxic materials is a best alternative. In this study, properties of CZTS deposited by low cost electrodeposition, layering of CZT with Sn as the underneath layer and a composite of Zn and Cu as the top layer, coupled with chemical bath in Na2S solution and then annealed under sulphur rich atmosphere were investigated. The optical band gaps of the annealed samples ranged between 1.59 to 1.94 eV with absorption coefficient in the order of ~104 cm-1 in the visible and near infrared range of the solar spectrum. The electrical sheet resistivity of the samples was observed to decrease with annealing temperature. The quality of the deposited CZTS was determined using Raman Spectroscopy, main peak at 338 cm-1 was observed for films annealed at 550 oC.