Carrier recombination dynamics in Ga0.51In0.49P double-heterostructures up to 500K
The bulk minority carrier lifetime and interface recombination velocity in GaInP double-heterostructures (DHs) lattice matched to GaAs are extracted using time-resolved photoluminescence (PL) measured between 300 and 500K. Effective lifetimes show a strong dependence on temperature for samples with insufficiently strong confinement potentials due to significant thermionic emission losses out of the DHs. An increased PL signal from the underlying GaAs layer relative to GaInP's PL at high temperatures supports this hypothesis. The impact is a shorter recombination lifetime which can be wrongly interpreted as a high interface recombination velocity of up to 4500 cm/s at 500K. These effects are investigated experimentally using samples of different barrier heights based on the Al-content in (AlxGa1-x)0.51In0.49P. A larger barrier height is shown to inhibit thermionic emission out of the DH, thus revealing a more accurate interface recombination velocity of 300 cm/s at 500K. The results are then used to develop a correction procedure to extract a more accurate interface recombination velocity at the barriers of the DH. Optoelectronic device simulations are used to gain insight into carrier dynamics as a function of temperature and the DH's barrier height, and confirm a strong inhibition of the thermionic emission losses as the Al-content is maximized in the barrier.