Characterization of Ag/TlInSe₂/Ag structure

Abstract

In this work, the current voltage characteristics of Ag/TlInSe2/Ag and In/TlInSe2/In structures, the incident light intensity and time dependencies of photocurrent as well as the response time-illumination intensity dependence of Ag/TlInSe2/Ag structures have been studied. For bias voltages larger than 1200. and 4.0 V, the current injection was found to be space charge limited and was assigned to the existing of deep and shallow hole traps being located at 210 and 16 meV for Ag and In-contacted samples, respectively. While indium-contacted samples show S-shaped I-V dependence above bias voltage of 10.0V, silver contacted samples does not show this behavior even at 200.0 V. For the Ag/TlInSe2/Ag structure, photocurrent was observed to exhibit stable values in a very short period of time. The device response time decreases with increasing illumination intensity, it exhibits a value of 0.13 s at incident light intensity of 53.6 mW cm(-2). The decrement in response time with increasing illumination intensity is associated with an increment in photocurrent at the same ratio. The ohmic behavior up to high voltages (120 V), the fast response time and the large spatial photocurrent make the Ag/TlInSe2/Ag structure promising IR detectors. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim