High photoresponsivity of a p-channel InGaP/GaAs/InGaAs double heterojunction pseudomorphic modulation-doped field effect transistor

In this letter, we report the electrical and optical characteristics of p-channel In0.13Ga0.87As double heterojunction pseudomorphic modulation-doped field effect transistor (MODFET) structure grown by gas source molecular beam epitaxy. The Hall mobility and the density of 2-DHGs (two-dimensional hole gases) in the pseudomorphic In0.13Ga0.87As channel were measured to be 250 cm(2)/V s and 1.9 x 10(12) cm(-2) at 300 K, and 5800 cm(2)/V s and 1.5 x 10(12) cm(-2) at 23 K, respectively. The fabricated p-channel MODFET shows a good mobility property which is due to high valence band discontinuity of InGaP/GaAs/InGaAs double barriers. The peak energy in the photoluminescence spectrum from the p-channel pseudomorphic MODFET structure was found to be 1.4 eV (lambda=881 nm). The photoresponsivity with this modified pseudomorphic MODFET structure shows outstandingly better than that of a pin photodiode, particularly at low incident optical power. (C) 1998 American Institute of Physics.