Abstract

An analysis of the AC characteristics of Al-GaAs/GaAs HEMT under illumination with modulated light has been carried out for small signal condition. A new model for the photovoltage calculation is outlined. The effect of the signal frequency on the photoconduc-tive current is evaluated, the results show that photo-conductive current is very small and can be neglected in calculation. The frequency dependence of photovoltage along with 2-DEG charge density, drain-source current and transconductance of the device have been studied analytically for HEMT structure.