InGaAs/InGaAlAs/InAs/InP very selective quantum dot infrared photodetector for 12 µm

Infrared photodetectors based on intersubband transitions in quantum dots (QDIPs) should, in principle, outperform the ones using quantum wells (QWIPs), because of the possibility of absorbing normal incident light and operating at higher temperatures due to the electron longer lifetimes. Additionally, the 3D confinement should lead to narrower transitions, desirable for sharper wavelength selective detection. In this communication we report the development of a QDIP which operates around 12 microns with a photocurrent peak as narrow as 6% for Δλ/λ. The absorption occurs between deep quantum dot states and the current generation, which is mediated by Auger scattering (1), relies on tunneling through the InP barriers via an adjacent quantum well.