EFFECT OF TIN PRECURSORS ON THE DEPOSITION OF Cu2ZnSnS4 THIN FILMS

Abstract

Cu2ZnSnS4 is a potential compound semiconducting material for solar absorber layer in thin film heterojunction solar cells. Chemical spray pyrolysis technique has been successfully employed to deposit these thin films using two different tin precursors. Thin films were characterized by studying their structural, composition, electrical and optical properties. X-ray diffraction pattern reveals that these films exhibit polycrystalline nature with kesterite structure. Lattice parameters of Cu2ZnSnS4 films are found to be a = b = 0.544 nm and c = 1.084 nm. Optical band gap, evaluated from spectral transmittance data, is close to ideal energy gap (1.5 eV) exhibit highest conversion efficiency. Optical absorption coefficient of these films is ≥ 104 cm-1 . These films exhibit p-type nature. A humble attempt is made to fabricate a typical heterojunction Cu2ZnSnS4 thin film solar cell.

Cu2ZnSnS4 Thin Film Solar Cell Construction Using Chemical Technique

“…Cu 2 ZnSnS 4 films were deposited using a precursor solution that included salts of cupric chloride (9x10 -3 M), zinc acetate (5x10 -3 M), stannic chloride (5x10 -3 M), and thiourea (5x10 -2 M) 19 . The excess thiourea in the precursor solution was deliberately higher than required to compensate for the sulfur loss during the experimentation.…”

“…An exhaust fan was incorporated into the fume cupboard to dissipate any generated gas fumes. The details of this experiment setup were discussed in our previous article 3,19 .…”