Thin-film (Pb,Sn)Se photodiodes for 8–12-μm operation

Abstract

Photodiodes have been made from thin films of p-type (Pb,Sn)Se on BaF2 substrates. Surface inversion using Pb barriers has given devices with D* (10.1 μm) ≳5×1010 cm Hz1/2 W−1 and D* (11.5 μ) ≳2×1010 cm Hz1/2 W−1 at 77 K with zero-bias resistance-area products up to 2 Ω cm2. Quantum efficiencies of the best devices were about 0.5.