Schottky‐barrier photodiodes were prepared by depositing either lead or indium ontop‐type PbSxSe1−xepitaxial films. These photodiodes had 77 °K zero‐bias resistance‐area products of 26–21 000 &OHgr; cm2asxvaried 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 &mgr;m 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.