A "Janus" double sided mid-IR photodetector based on a MIM architecture

Abstract

We present a mid-IR ($\hat{I}»\approx$ 8.3 $\hat{I}¼$m) quantum well infrared photodetector (QWIP) fabricated on a mid-IR transparent substrate, allowing photodetection with illumination from either the front surface or through the substrate. The device is based on a 400 nm-thick GaAs/AlGaAs semiconductor QWIP heterostructure enclosed in a metal-insulator-metal (MIM) cavity and hosted on a mid-IR transparent ZnSe substrate. Metallic stripes are symmetrically patterned by e-beam lithography on both sides of the active region. The detector spectral coverage spans from $\hat{I}»\approx 7.15$ $\hat{I}¼$m to $\hat{I}»\approx 8.7$ $\hat{I}¼$m by changing the stripe width L - from L = 1.0 $\hat{I}¼$m to L = 1.3 $\hat{I}¼$m - thus frequency-tuning the optical cavity mode. Both micro-FTIR passive optical characterizations and photocurrent measurements of the two-port system are carried out. They reveal a similar spectral response for the two detector ports, with an experimentally measured T${}_{BLIP}$ of $\approx$ 200K.

Copyright 2021 Mario Malerba, Mathieu Jeannin, Stefano Pirotta, Lianhe Li, Alexander Giles Davies, Edmund Linfield, Adel Bousseksou, Jean-Michel Manceau and Raffaele Colombelli. This article is distributed under a Creative Commons Attribution (CC BY) License. The following article has been submitted to APL Photonics. After it is published, it will be found at https://aip.scitation.org/journal/app