Significantly improved carrier lifetime and reduced interface recombination velocity for CdTe/MgCdTe double heterostructures

The carrier lifetime of CdTe/MgCdTe double heterostructures has been enhanced significantly up to 2.1 μs through using 30 nm Mg_0.48Cd_0.52Te barriers. Temperature-dependent photoluminescence measurements indicate that the radiative recombination contributes significantly to the total recombination at room temperature, and the internal quantum efficiency is estimated to be 40 %. A radiative and a non-radiative lifetimes have thus been calculated to be 5.25 μs and 3.5 μs, respectively. The interface recombination velocity of CdTe/Mg_0.48Cd_0.52Te is determined to be smaller than 2.7 cm/s, which is better or very close to the best values reported for GaAs/AlGaAs and GaAs/Ga_0.5In_0.5P double heterostructures.