INTERSUBBAND PHOTOCURRENT FROM DOUBLE-BARRIER RESONANT-TUNNELING STRUCTURES

Simple models of semiconductor-based double barrier resonant tunneling structures predict a large accumulation of charge carriers in the str ucture. These carriers can be excited optically from one subband to an other generating photocurrent. In this work we have investigated the p hoto-induced current due to intersubband excitation in double barrier structures. We have found that the origin of the photocurrent is accum ulation of quantized carriers in the emitter-barrier junction of the s tructure, rather than accumulation of carriers in the double barrier q uantum well. This photon assisted tunneling process in double barrier structures may be used for infrared detection. (C) 1996 Academic Press Limited