Auger recombination in Cd0.2Hg0.8Te and the effect of background radiation on its measurement

Band to band electron-electron (CCCH) and light hole-heavy hole (CHLH) Auger transition rates, lifetimes and coefficients have been computed for degenerate and non-degenerate n- and p-type Cd 0.2 Hg 0.8 Te in the temperature range 3-200 K. No approximations beyond the use of quasi-Fermi levels and the overlap function term of the four-band k.p matrix element have been made. Good agreement with experiment is obtained. The possible effect of 300 K background radiation on measured recombination times is discussed and estimated on a simple model. It is shown that there can be a considerable reduction in recombination time at very low temperature, particularly for n-type samples, if care is not taken to reduce the background to extremely low levels.