Aspects of Numeral Value of Cu 2 ZnSnS 4 (CZTS) Absorber Layer Fabricated in Sol-gel Process by Dip Coating Technique

This paper represents the analysis of structural and optical properties of CZTS films grown by dip-coating and its application as an absorber in thin film solar cells. The CZTS thin films were prepared in ordinary glass substrates for a different number of depositions. The optical band gap and absorption coefficient of a CZTS absorber layer related to the concentration of aqueous precursors containing copper (II) chloride dehydrate (CuCI 2 .2H 2 O), zinc (II) chloride (ZnCI 2 ), tin (II) chloride (SnCI 2 ) and thiourea (CS(NH 2 ) 2 ) were determined. The solution was prepared by dissolving cation metal salts and thiourea in 2-methoxyethanol and monoethanolamine. It is observed that two times deposited film shows good quality Kesterite structure of CZTS is revealed by the XRD. Optical identifications have been carried out using UV-Vis spectroscopy techniques. The direct band-gap of 1.48 eV was found in one sample which is very close to the optimal value as an absorber layer and absorption coefficient was found greater than 104 cm-1 which establish the characteristics of leading CZTS phase in the film.