Temperature and Injection Dependence of Photoluminescence Decay in Midwave Infrared HgCdTe

Abstract

Photoluminescence decay (PLD) measurements have been performed on mid-wave infrared (MWIR) Hg-vacancy p-doped HgCdTe samples at temperatures ranging from 85 K to 330 K. The doping level is $$p_{0} = 6 \times 10^{15} \;{\hbox{cm}}^{ - 3}$$ at 80 K and the cut-off wavelength is $$\lambda_{\rm{c}} = 4.2\;\upmu{\hbox{m}}$$ at 300 K. The PLD signal has been fitted with a photo-injection level dependent model in order to estimate the contributions from the different recombination mechanisms to the total minority carrier lifetime. Shockley–Read–Hall centers lying in the bandgap at 25 meV from the conduction or the valence band has been found to limit the minority carrier lifetime from 85 to at least 200 K. The value of the Auger 1 lifetime coefficient is extracted from the first instants of signal decay for each temperature and reaches $$G_{\rm{eei}} n_{i}^{ - 3} = 5 \times 10^{ - 26} \;{\hbox{cm}}^{6} \;{\hbox{s}}^{ - 1}$$ at 85 K. The temperature evolution of the different contributions to the lifetime are in accordance with dark current density measurements in HgCdTe photodiodes.