Intrinsic carrier losses in tellurium due to radiative and Auger recombinations

Abstract

Fully microscopic many-body models based on inputs from first principles density functional theory are used to calculate the carrier losses due to radiative- and Auger-recombinations in bulk tellurium. It is shown that Auger processes dominate the losses for carrier densities in the range typical for applications as lasers. The Auger loss depends crucially on how far energetically lower hole bands are detuned from the valence band edge. Values for this detuning range throughout literature from being about equal to the bandgap to being on the order of 100 meV larger than the bandgap. We find that at cryogenic temperatures of 50 K (100 K), the Auger coefficient, C, is about six (three) orders of magnitude smaller if this detuning is as in our calculations at the low end of the published values rather than at the high end where it exceeds the bandgap. At room temperature, the sensitivity is reduced to about a factor of four with C values ranging between 0.4 and 1.6×10−27 cm6 s−1. Here, radiative losses dominate for carrier densities up to about 1016/ cm3 with a loss coefficient B≈10−11 cm3 s−1. The radiative losses are about two to three times lower than in typical bulk III–V materials for comparable wavelengths.