Infrared photoluminescence of arsenic-doped HgCdTe in a wide temperature range of up to 290 K

Infrared modulated photoluminescence (PL) spectra are recorded in the temperature range of 11. 5 - 290 K for both as-grown and p-type annealed arsenic-doped narrow-gap HgCdTe epilayers prepared by molecular beam epitaxy. Curve fittings indicate that conduction band-to-valence band transition is just detectable at 77 K but will dominate the PL line shape at temperatures above about 200 K. Below 100 K, transitions are mainly impurity-related. Shallow impurity levels are estimated to be about 12, 20, 17, and 26 meV, respectively, for V Hg and As Te as acceptors, and As Hg and Te Hg as donors, which are very similar to those established by theory and/or infrared photoreflectance spectroscopy. The p-type annealing removes deep level-related PL features that are only observed in the as-grown HgCdTe epilayer. Comparison with previous PL study suggests that infrared modulated PL technique can serve as an easily accessible pathway for characterizing impurities in narrow-gap HgCdTe when PL spectra are recorded with good signal-to-noise ratio in a wide range of up to room temperature.