Photoinduced electrical bistability of sputter deposited CdZnTe thin films

CdZnTe thin films were fabricated on glass substrates by sputtering and the potentiality of photoinduced electrical data storage was investigated. As deposited film was annealed to enhance the crystallization and both the as deposited and annealed films were characterized by XRD, RAMAN, UV-vis-NIR, PL, FESEM and EDAX analysis. Optical and electrical properties of the films were investigated in detail. The thin films show interesting photo induced electrical bistability. The electrical bistability was observed with symmetric lateral electrodes under illuminated condition only. In the dark, forward and reverse bias curves traced the same path but under light illumination condition there is a substantial difference in the I-V traces of the forward and reversed biased conditions. After annealing the crystallinity of the as deposited film improved and the ON-OFF ratio of electrical bistability increased considerably. This phenomenom could be useful for light sensitive RAM type devices.