Multicolor voltage-tunable quantum-well infrared photodetector

Abstract

A novel concept for a quantum-well infrared photodetector (QWIP) with a spectral response peak tunable by an external voltage is described and tested experimentally. This multicolor detector structure is made by stacking conventional (one-color) QWIPs, separated by thin, heavily doped layers ( approximately=90 nm in the test structure). The most important feature is that externally applied DC voltage is distributed among the different one-color QWIPs according to their DC resistances. Each one-color QWIP therefore turns on sequentially in the order determined by its resistance.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>