  The changes in excitation dependence of efficiency with temperature is
modeled for a wurtzite InGaN light-emitting diode. The model incorporates
bandstructure changes with carrier density arising from screening of
quantum-confined Stark effect. Bandstructure is computed by solving Poisson and
k.p equations in the envelop approximation. The information is used in a
dynamical model for populations in momentum-resolved electron and hole states.
Application of the approach shows the interplay of quantum-well and barrier
emissions giving rise to shape changes in efficiency versus current density
with changing temperature, as observed in some experiments.
