Photoconduction studies on InGaAs HEMTs

Photoconduction measurements made on In/sub 0.53/Ga/sub 0.47/As channel HEMTs indicate that the threshold energy for photoconduction corresponds to the bandgap of the quantum well and the absorption edge of the substrate. Many interband transitions are observed which can be correlated with the electronic subbands of the quantum well. Strong confinement of photogenerated holes is associated with a large modulation of the HEMT threshold voltage.