TEMPERATURE-DEPENDENCE OF PHOLOLUMINESCENCE LIFETIMES IN ORDERED GAINP

The temperature dependence of carrier lifetimes in ordered (o) GaInP2 epilayers was investigated with and without cladding layers of disordered (d) GaInP2. The extremely long lifetime of the emission that moves with laser excitation density and the shorter lifetime of the nonmoving emission persist up to T=50 and 300 K, respectively. Both decays involve localized holes. By removal of the d top layer of the double heterostructure, an enhanced hole diffusion to the surface occurs, which results in a slightly faster, nonexponential decay. It is argued that, within the nominally o layer, a type II recombination occurs and that o and d GaInP2 exhibit a type II band lineup. The appropriate band curvatures in the d top layer cause hole localization at the d side of the o-d interfaces. The minority carrier lifetime shows two-dimensional behavior between T=70 and 170 K, and decrease above 170 K.© 1995 American Institute of Physics.