THEORY OF QUANTUM-WELL IN PHOTODETECTORS WITH TUNNELING ELECTRON INJECTION

A simple analytical model of quantum-well infrared photodetectors (QWI Ps) utilising intersubband electron transitions and tunnelling injecti on of electrons is developed. It is shown that the dark current and th e responsivity as functions of the QWIP parameters, including the numb er of QWs, are expressed by means of solutions of a transcendent equat ion. This equation is valid for a wide range of parameters and conditi ons where QWIPs can exhibit effective operation. Explicit formulae for the dark current and the responsivity are obtained in some important cases. Nonlinear effects in the QWIP operation are considered and thre shold Values of bias voltage and intensity of infrared radiation are e stimated.