Effects of Ionic Immersion Time on Optical Properties of Cu2ZnSnS4(CZTS) Deposited by Successive Ionic Layer Adsorption and Reaction (SILAR)

Abstract

Cu2ZnSnS4(CZTS) thin films fabricated by successive ionic layer adsorption and reaction (SILAR) method is a promising combination to actualize a low cost thin films Solar Cell (TFSC). Ionic exchange and rinsing time are critical point for ionic layer formation in SILAR method. The purpose of this study is to investigate the influence of cationic and anionic immersing time on the band gap energy of CZTS. Immersing time was varied into 10, 20, 30 and 40 seconds for both deposited and annealed samples, which annealing was conducted on 300°C for two hours. Deposited results showed a linear increase on band gap energy as cationic immersing time extended. Whereas, nonlinear increment with optimum band gap 1.35eV at 30 seconds immersion happened for anionic time variation samples. Annealed CZTS with cationic time variation also showed a linear increasing band gap. Meanwhile, annealed with anionic time variation showed a backward tendency of the deposited samples which the band gap decrease nonlinearly as anionic immersing time lengthened.