Deposition of Cu2ZnSnS4 (CZTS) prepared by a solution route for solar cells applications

As a promising candidate as absorber layer in thin film solar cells,the cu2znsns4 (czts) material has gained a broad interest over recent years for the production of low-cost solar cells due to its direct and tunable band gap energy,high optical absorption coefficients and also due to the abundance and the non-toxicity of all its constituents. in addition,to solve the problem of expensive and complicated vacuum-based synthesis methods,simple and low-cost methods have been developed for the preparation of this material. in this present work,the czts thin films have been prepared using a solution route namely sol-gel,which is a simple and low cost method for a large production of thin films materials and spin coated onto glass substrates. the sol-gel precursor solution was made from metal salts of copper (ii) chloride (cucl2),zinc (ii) chloride (zncl2),tin (iv) chloride (sncl4),and thiourea (cs (nh2)2) dissolved into a mixture of ethanol/water as solvent. the x-ray diffraction studies showed the formation of a kesterite structure with peaks corresponding to (112) and (220) directions. the raman spectrum indicated the presence of the principal kesterite peak at 336 cm-1 and the existence of a strange peak at 424 cm-1 which could be attributed to the binary compound cu2s. the absorbance spectrum has been recorded for the estimation of the band gap. the czts thin film can be made using a simple spin coating technique,but improvements in the film properties by a suitable annealing time and temperature as well as annealing environment and post deposition needs have to be done for making a quality photovoltaic absorber.