High-energy and recombination-induced electroluminescence of InAlAs/InGaAs HEMT's lattice-matched to InP substrates

We report room-temperature measurements of the high-energy electroluminescence (EL) of InAlAs/InGaAs HEMT's lattice-matched to InP substrates. We found that both the carrier temperature and the intensity obtained from the EL signal for the 1.4-1.7 eV energy range drastically increases with increasing the variation in the potential at the drain edge in the channel. The observed features are consistent with the results of the spatial distribution measurement, which indicates that the EL comes from the drain edge. We further compared the bias-voltage dependence of the high-energy EL and the recombination-induced EL measured for the same device, and discussed the origin and the threshold energy of the respective luminescent processes.