Recombination dynamics of carriers in an InGaN/AlGaN single-quantum-well light-emitting diode under reverse-bias voltages

The radiative recombination process of the blue emission band in an InGaN s ingle-quantum-well light-emitting diode has extensively been investigated b y means of the dependence of an external electric field on photoluminescenc e and time-resolved photoluminescence spectra. Two emission (higher and low er) components separated by about 40 meV are found in the emission band on the condition of reverse bias at 77 K. It is also found that the luminescen ce intensity decreases dramatically with increasing reverse-bias voltage at room temperature. The model based on field ionization of excitons cannot e xplain the present experimental phenomena. It is, therefore, suggested that the free-carrier recombination process is dominant at room temperature. (C ) 2000 American Institute of Physics. [S0003-6951(00)01712-5].