PREPARATION OF CZTS THIN FILM EMPLOYING RAPID THERMAL PROCESSING METHOD

Abstract

CZTS thin film was fabricated by sulfurization process of deposited thin films on Mo coated glass substrates. Cu, Zn, and Sn thin film layers were deposited sequentially to form Glass/Mo/CuSn/Zn/Cu. The CuSn layer in the stacked structure was formed by annealing process in the sputtering chamber after sequential deposition of Cu and Sn, respectively. The sulfurization process was performed by rapid thermal processing method (RTP) so as to obtain kesterite CZTS structure. The obtained CZTS thin film was analyzed using several characterization methods such as EDX, XRD, Raman spectroscopy, SEM and PL measurements. The EDX measurements showed that elemental loss was not observed after the annealing process in sulfur atmosphere. The fabricated CZTS thin film showed Cu stoichiometric and Zn rich composition. The XRD pattern of annealed sample revealed formation of kesterite CZTS structure. The Raman spectra of the sample proved formation of kesterite CZTS structure. In addition, some CTS phases were detected in the structure by Raman spectroscopy. Polycrystalline surface microstructure was seen in SEM surface measurement. The room temperature PL measurement exhibited a transition around at 1.39 eV that is very close to band gap of kesterite CZTS structure. Overall, with this study, it has been shown that the CZTS thin film structure can be easily produced using the RTP method with very high heating rate.