Composition-tuned PbSxSe1−x Schottky-barrier infrared detectors

Abstract

Schottky‐barrier photodiodes were prepared by depositing either lead or indium onto p‐type PbS_xSe_1−x epitaxial films. These photodiodes had 77 °K zero‐bias resistance‐area products of 26–21 000 Ω cm² as x varied from 0 to 1, respectively. The peak detectivities were close to the background limit and could be composition tuned between 3.7 and 6.9 μm at 77 °K. Narrowband detectors were prepared by using one film as a short‐wavelength cutoff filter and a second film, of slightly different composition, as the detector. These devices exhibit high quantum efficiencies, low half‐bandwidths, and insensitivity to variations in incident angle.