Synthesis of Cu₂ZnSnS₄ thin films by dip-coating method without sulphurization

Quaternary Cu₂ZnSnS₄ (CZTS) thin films, a promising absorber material for solar cells has been successfully deposited on glass substrates by cost effective simple dip-coating method without using either polluting chemicals or expensive vacuum facilities. X-ray diffraction pattern reveals the formation of CZTS films with tetragonal type kesterite structure. The Raman spectra of the prepared films exhibited resonance peaks corresponding to the CZTS phase. The scanning electron microscopic image shows the formation of films with smooth surface. The surface topography studied using atomic force microscope gives an rms roughness of 1.6 nm. The Hall effect studies indicate that the prepared films are p-type with a carrier concentration of 4.77 × 10²⁰ cm⁻³. The energy dispersive X-ray analysis result indicate the presence of Cu, Zn, Sn and S in the film. The absorption coefficient was found to be the order of 10⁴ cm⁻¹ and the band gap has been found to be 1.5 eV.