Doping the bismuth into the host’s Cu2ZnSnS4 semiconductor as a novel material for thin film solar cell

In this report for the first time, the Cu2Zn1-xBixSnS4 (CZBiTS) semiconductor at (0 <= x <= 1) has been synthesized using the solvothermal and spin coating methods. The structural, optical, morphological and electrical properties of CZBiTS semiconductor were investigated. It was found that the Cu2BiSnS4 (x = 1) (CBiTS) thin film was better than the Cu(2)(Z)nSnS(4) (x = 0) (CZTS) and CZBiTS (x = 0.25, 0.5 and 0.75) thin films due to its optimum features like higher absorption coefficient ( > 10(4) cm(-1)), higher optical conductivity, lower transmittance and lower band gap (1.25 eV). Furthermore, the CBiTS thin film was more uniform, improved and had large grains so; it was observed the number of grains in the CBiTS film, 0.038 nm(-2), were lower than that, 6.8 nm(-2) of the CZTS film. Also, the dislocation density in the CBiTS film, 0.0007 nm(-2), was lower than that, 0.024 nm(-2) of the CZTS film resulting in decreasing the defects in the grain boundaries and increasing the current from 0.34 mA for the CZTS film to 0.48 mA for the CBiTS film. Based on the observed results, authors considered the CBiTS thin film as a novel material and competitor for the CZTS thin film and can be used as an absorbent layer to sunlight in thin film solar cell.