| Popis: |
The radiative recombination mechanism in InGaN single-quantum-well (SQW) blue light-emitting diodes (LEDs) andInGaN double heterostructure (DH) ultraviolet (UV) LEDs has extensively been investigated by means ofthe dependence ofphotoluminescence (PL) and time-resolved PL (TRPL) spectra on an external-electric field. Two emission components arefound in the luminescence spectra from each LED on the condition of reverse-bias at 77 K. It is also found that theluminescence intensity of the LEDs decreases dramatically with increasing reverse-bias voltage at room temperature (RT).The model based on field ionization of excitons cannot explain the present experimental phenomena. It is thereforesuggested that the free-carrier recombination process is dominant at RT. We have also suggested that these experimentalresults on the blue and UV LEDs can be explained by the same recombination model. Finally, on the basis of both theexperimental evidence in In003Ga092N epitaxial layers and strong electron-phonon interaction, the radiative recombinationmechanism on InGa1N ternary alloys has been discussed.Keywords : InGaN, Reverse bias, Time-resolved luminescence, Recombination, Electron-phonon interaction |
