Defects Characterization of HgCdTe and CdZnTe Compounds by Positron Annihilation Spectroscopy

Infrared cooled photodetectors must operate at higher temperatures to reduce their size, weight and power consumption (SWaP context). Their stability image quality are then challenged by extra electrical activity of crystal defects. Knowledge defect populations is mandatory improve the material epitaxial Hg1−xCdxTe (MCT) active layer Cd1−xZnxTe (CZT) substrate. Positron annihilation spectroscopy with a slow positron beam was used study near-surface open-volume defects profiles. Low- high-momentum fractions ( $$S$$ , $$ W$$ ) were characterize Doppler broadening 511 keV electron-positron pair annihilation-line as function implantation energy $$E$$ . The results show that three regions can be identified beneath surface as-grown non-optimized MCT layer. quasi-linear relationship between characteristics in suggests mainly correspond same different concentrations. probed thought related mercury vacancy. This hypothesis discussed an original way elemental profiles using scanning transmission electron combined dispersive x-ray (STEM-EDX). Afterwards, this approach extended CZT substrates showing bulk properties those fabricated LYNRED tend match state-of-the-art. A common probed, concentration estimated Hall effect around 1015 cm−3 cadmium