CONTACT AND DISTRIBUTED EFFECTS IN QUANTUM-WELL INFRARED PHOTODETECTORS

We propose a simple distributed model for intersubband quantum well in frared photodetectors (QWIPs), which explicitly takes into account the injecting properties of the contacts. We show that the QWIP operation with multiple QWs involves the formation of a high-field domain near the emitter, caused by the modulation of the bound electron density in the QWs by applied voltage and infrared radiation. The external chara cteristics of the QWIP (total current, differential resistance, and qu asistatic capacitance) are strong functions of the voltage and radiati on intensity. (C) 1995 American Institute of Physics.