Narrow-gap piezoelectric heterostructure as IR detector

Abstract

Narrow-gap mercury cadmium telluride thin films grown by MBE and LPE methods onto various substrates (HgCdTe/Si, HgCdTe/GaAs, HgCdTe/CdZnTe) were investigated as a piezoelectric heterostructure for IR detection. The photoresponse, infrared transmittance spectra, parameters of the charge carrier transport, and mechanical properties were studied. Mechanical stresses at the layer-substrate interface were analyzed. HgCdTe-based infrared device is considered, operating in the middle (3–5 μm) infrared spectral range without cryogenic cooling to achieve performance level D* = 2.6 ⋅ 10⁹ ⋅ W⁻¹ cm ⋅Hz¹/² The possibility to detect infrared radiation is thought to be based on the possibility of the spatial separation of the non-equilibrium carriers in the strained semiconductor heterostructure with piezoelectric properties.