Temperature and magnetic field effect on oscillations observed in GaInNAs/GaAs multiple quantum wells structures

Abstract

The photoconductivity of p-i-n GaInNAs/GaAs multiple quantum well (MQW) mesa structures is investigated. When illuminated with photons at energy greater than the GaAs bandgap, a number of oscillations are observed in the current-voltage I-V characteristics. The amplitude and position of the oscillations is shown to depend upon the temperature, as well as upon the exciting wavelength and intensity. Due to the absence of the oscillations in the dark I-V and at temperatures above T=200 K, we explain them in terms of photogenerated electrons escaping from quantum wells via tunnelling or thermionic emission.