By inductively coupled plasma (ICP) etching, a selective high barrier region (SHBR) was fabricated below the p-pad metal electrode for modifying the injection current distribution on p-type GaN of GaN-based light-emitting diodes (LEDs). Through the analysis of current noise power spectra, the samples with ICP etching treatment have excess nitrogen vacancies at the selectively etched surface of p-type GaN; thus, they have a lower hole concentration than the as-grown sample, resulting in a larger barrier height for carrier transport. With this SHBR, the light-output power for the LED chip measured at 20mA was significantly increased by 12% as compared with that for the conventional LED chip. The light-output power increase could be attributed to a relative reduction in optical power absorption under the p-pad electrode and a higher density of current effectively injected into the active layer of the LED by the SHBR structure.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)