Sweeping-rate-dependent photocurrent of GaAs Schottky diode with strain relaxed InAs quantum dots

Abstract

We demonstrate that the photocurrent of a GaAs Schottky diode can be influenced by the carrier stored in strain relaxed InAs quantum dots (QDs) embedded in the Schottky diode. A potential drop is induced by the charged QDs, and the photocurrent generated from the Schottky diode can be suppressed by the induced potential drop. In this paper, the charging time of the relaxed InAs QDs is obtained from 0.1 to 10 s. So the variation in photocurrent can be detected, if the sweeping rate of applied bias is from 10 to 0.1V/s. Two kinds of QD samples, relaxed and non-relaxed InAs QDs, are compared, and we found that the photocurrent is obviously influenced in the relaxed InAs QD sample. A equivalent RC circuit modal also is provided to analyze the formula of the photocurrent, and the analysis agrees with the results of measurements. This study is advantageous for the investigation of QD memory devices. (C) 2015 The Japan Society of Applied Physics