Study on the physical properties of Cu₂ZnSnS₄ thin films deposited by pneumatic spray pyrolysis technique

The acquisition of new materials for the manufacturing of high efficiency and low-cost photovoltaic devices has currently become a challenge. Thin films of CuInGaSe and CdTe have been widely used in solar cell of second genera-tion, achieving efficiencies about 20 %; however, the low abundance of In and Te as well as the toxicity of Cd is the primary obstacles to their industrial production. Compounds such as Cu₂ZnSnS₄, Cu₂ZnSnSe₄ and Cu₂ZnSn(SSe)₄ have emerged as an important and less costly alternative for efficient energy conversion in the future. In addition, these compounds have the required characteristics to be used as an absorber material in solar cells (band-gap close to 1.4 eV, an absorption coefficient greater than 10⁴ cm^-1 and a p-type conductivity). In this work, we present a study of the struc-tural, compositional, morphological and optical properties of Cu2ZnSnS4 thin films deposited by spray pyrolysis tech-nique as well as their dependence on temperature.