Photoelectrochemical Properties of Spray Deposited Cu2ZnSnS4 Photoelectrode: Enhancement in Photoconversion Efficiency with Film Thickness

J. P. Sawant,1*Email 

H. M. Pathan2 

R. B. Kale3

1Department of Physics, University of Mumbai, Santacruz (E), Mumbai – 400098, India

2Deperatment of Physics, Institute of Science, Madam Cama Road, Fort, Mumbai 400032, India

3 Advanced Physics Laboratory, Department of Physics, Savitribai Phule Pune University, Pune- 411 007

Abstract

Cu2ZnSnS4 (CZTS) thin films were deposited using the spray pyrolysis method at different deposition conditions. The effects of molarity of precursor solution and film thickness on structural, morphological, composition, optical and photoelectrochemical cell (PEC) performance of CZTS thin films were investigated. The X-ray diffraction study showed that the polycrystalline nature of the kesterite phase CZTS with a tetragonal structure and the average crystallite size was estimated around 26 nm. The scanning electron microscope (SEM) analysis revealed uniform, dense and compact film deposited on the substrate surface. The films exhibited a direct energy band gap (Eg) around 1.54 eV, and the elemental composition ratio was found to be Cu/(Zn+Sn) = 0.97 and Zn/Sn = 1.04. The effect of elemental composition and the thickness of CZTS films on photoelectrochemical properties were investigated. The PEC cell fabricated using CZTS photoelectrode exhibited a photocurrent density of 11.12 mA/cm2 with a power conversion efficiency of 2.70%.

Photoelectrochemical Properties of Spray Deposited Cu2ZnSnS4 Photoelectrode: Enhancement in Photoconversion Efficiency with Film Thickness