Preparation of High Quality n-Hg0.8Cd0.2Te Epitaxial Layer and Its Application to Infrared Detector (λ=8–14 µm)

High mobility n-type Hg0.8Cd0.2Te liquid phase epitaxial layers on CdTe substrates are reproducibly obtained by annealing the layers under Hg overpressure and then by diffusing indium into the annealed layers. Their carrier concentrations and Hall mobilities are in the range of (1.5–2.0)×1015 cm-3 and (1.0–1.5)×105 cm2/Vs, respectively at 77 K. A photoconductivity-type IR detector using one of these layers has detectivity Dλ* higher than 2×1010 cmHz1/2/W in the wavelength region of 8–14 µm with a peak detectivity Dλp* of 3×1010 cmHz1/2/W at 13 µm.