Comprehensive Numeric Study of Gallium Nitride Light-Emitting Diodes Adopting Surface-Plasmon-Mediated Light Emission Technique

The coupling of quantum well (QW) spontaneous emissions to surface plasmons (SPs) has been a promising technique to increase emission rate of LEDs. We carried out numeric investigations to explore the electromagnetic nature of these SP modes. It has been shown that the SP resonance frequency on a flat silver/GaN interface, and hence the corresponding emission enhancement factor can be easily tuned by altering the thickness of silver film and the separation between QW and metal. By using coupled SPPs, partial energy transfer across silver film can be achieved, where strong directional light emission can be re-emitted. We also utilized semiconductor simulation technique to investigate the internal operations of our proposed LED. We found that the internal inefficiency of the device might be attributed to the current crowding effect, poor carrier injection, as well as bad overlap of electron and hole wave functions inside the well. The combination of electromagnetic and semiconductor simulation techniques has been presented as a powerful tool in theoretical analysis of SP-mediated emission LED.