Characterization of photoresponse, photovoltage, and photonic gate response in a pseudomorphic p-channel modulation-doped field-effect transistor

Optoelectronic responses in a pseudomorphic p-channel modulation-doped field-effect transistor (p-MODFET) on GaAs have been characterized. Semiempirical models are provided and verified with experimental data. Significantly suppressed drain photoresponse and reduced gate photoresponse have been observed in p-MODFET due to the low hole mobility and high Schottky barrier on the InGaP layer. The drain photoresponse is predominantly modulated by the photoconductive effect of excess majority carriers while the photovoltage and photonic gate response are governed by the photovoltaic effect caused by excess minority carriers and energy barriers between the channel and dopant layers. (C) 2000 American Institute of Physics. [S0003-6951(00)00451-4].