Parallel conduction and non-linear optoelectronic response of an n-channel pseudomorphic high electron mobility transistor

Abstract

Oploelectronic properties of an n-channel Al0.3Ga0.7As/GaAs/In0.13Ga0.87As pseudomorphic high electron mobility transistor (PHEMT) have been characterized as a function of the drain voltage, the gate voltage and an optical stimulation with a wavelength lambda = 830 nm. Physical mechanisms involved in the variation of optoelectronic performance are discussed and analytical models are provided for strong non-linear photoresponsivity. Parallel conduction caused by free electrons in the N-type Al0.3Ga0.7As donor layers, which is qualitatively explained and analytically modeled, is believed to be one of the most dominant processes in the non-linear optoelectronic response of PHEMTs under high optical stimulation. (C) 1999 Elsevier Science Ltd. All rights reserved.