Growth of Cu2ZnSnS4 Thin Film Solar Cells Using Chemical Synthesis

Abstract

Objectives: Cu2ZnSnS4 thin film solar cell is fabricated by using the chemical spray pyrolysis method. Method: CZTS thin films were successfully deposited by employing the eco-friendly and cost-effective chemical spray pyrolysis method. X-ray diffraction (XRD) and Raman spectroscopy are used to investigate the structural properties of the prepared samples. The surface morphology of the deposited films is studied using a scanning electron microscope. An energy dispersive spectrometer is used to know the chemical compositions of the deposited films. A double beam spectrophotometer is used to study the optical characteristics of these films. The hot probe technique is used to confirm the nature of the conductivity of the deposited films. Findings: The XRD spectra of the thin films reveal the polycrystalline nature with the kesterite structure of the thin films. The optical band gap is found to be 1.52 eV and the absorption coefficient value of these films is found to be  104 cm-1. The nature of conductivity is identified to be p-type. Finally, Cu2ZnSnS4 thin film solar cell is fabricated with the substrate configuration glass/Mo/CZTS/CdS/Ag which exhibited an open circuit voltage and short circuit current of 156 mV and 1.82 mA/cm2 respectively. Novelty: The growth of Cu2ZnSnS4 thin films is studied by varying the distance between the spray nozzle and glass substrate from 25 to 35 cm in steps of 5 cm and maintaining all other parameters as constant. Finally, the Cu2ZnSnS4 thin film solar cell is prepared in a substrate as well as a superstrate configuration. Keywords: Thin films; Absorber layers; Spray technique; Solar cell; Cu2ZnSnS4