HIGH-FREQUENCY RESPONSE OF INTERSUBBAND INFRARED PHOTODETECTORS WITH A MULTIPLE-QUANTUM-WELL STRUCTURE

We have theoretically studied the response of quantum well intersubban d photodetectors to high-frequency modulated infrared radiation. The s mall-signal responsivity dependent on the modulation frequency of infr ared radiation and device parameters has been derived using the propos ed analytical model. It has been shown that with increasing modulation frequency the roll-off of the small-signal responsivity is associated with the electron transit and capture effects which limit the device bandwidth.