High resistance narrow band quantum cascade photodetectors

Abstract

A high resistance narrow band quantum cascade photodetector (QCD) is presented. Leakage current has been suppressed, increasing the resistivity, thanks to a design in which coupling barriers have been thickened. Useless cross transitions have been eliminated finally leading to a Johnson noise detectivity at 50 K comparable to quantum well infrared photodetectors. Because they work with no dark current, QCDs are very promising for small pixel and large focal plane array applications.