Temperature dependence of intensity and peak position from photocurrent response in p-CdIn2Te4 crystal

A p-CdIn2Te4 crystal has been investigated using photocurrent (PC) spectroscopy as a function of temperature. The three peaks are associated with band-to-band transitions. In addition, the PC intensities were observed to decrease with decreasing temperature. This is attributed to the trapping centers due to native defects and impurities in the p-CdIn2Te4 on the basis of Simmons and Taylor's theory [J. Phys. C 7, 3051 (1974)]. From the relation of log J(ph) vs 1/T, where J(ph) is the PC density, the exponential variation of the PC with varying temperature showed that there are two dominant levels in the high- and moderate-temperature region. However, the PC signal in the low-temperature region below 50 K remains constant. Finally, the temperature dependence of the optical band gap of the p-CdIn2Te4 obtained from the PC measurement has been precisely estimated. (C) 2004 American Institute of Physics.