Quantum-Well Infrared Phototransistor With pHEMT Structure

摘要

A quantum-well infrared phototransistor with a pseudomorphic high-electron mobility transistor (pHEMT) structure is presented. The proposed phototransistor uses four periods of a GaAs/Al{sub}(0.3)Ga{sub}(0.7)As (50 A/120 A) quantum-well absorption region, as well as an In{sub}(0.15)Ga{sub}(0.85)As quantum well conducting channel under the absorption layer. The phototransistor shows a large responsivity of 140 AAV around 6 μm at 23 K (for a cutoff wavelength of 7.5 μm). The relation between the photoconductive gain and the transconductance of the pHEMT structure is also investigated.