Time-resolved electroluminescence of AlGaN-based light-emitting diodes with emission at 285 nm

We present a study on the time evolution of the electroluminescence (EL) spectra of AlGaN-based deep ultraviolet light-emitting diodes (LEDs) under pulsed current pumping. The EL spectra peaks at 285 nm and 330 nm are found to result from recombination involving band-to-band and free carriers to deep acceptor level transitions. The 330 nm long-wavelength transitions to deep acceptor levels in the p-AlGaN layer as well as the nonradiative processes significantly influence the LED internal quantum efficiency. (C) 2003 American Institute of Physics.