InGaN/GaN quantum well interconnected microdisk light emitting diodes

Abstract

Interconnected microdisk light-emitting diodes (μ-LEDs) have been fabricated from InGaN/GaN single quantum wells grown by low pressure metal organic chemical vapor deposition. These interconnected μ-disk LEDs fit into the same device area taken up by a conventional broad-area LED. The performance characteristic of these interconnected μ-disk LEDs, including $\mathrm{I–V}$ and $\mathrm{L–I}$ characteristics as well as electroluminescence spectra have been measured and compared with those of the conventional broad-area LEDs. For interconnected μ-disk LEDs, while $V_F,$ the forward biased voltage at 20 mA, was slightly increased, the emission efficiency was increased by as much as 60% over the conventional LEDs for a fixed device area. The results thus suggested that replacing a conventional broad-area LED with an interconnected μ-disk LED, the external quantum efficiency can be significantly enhanced. Finally, the fabrication processes of the interconnected μ-disk LEDs are almost the same as those of the conventional broad-area LEDs. It is thus expected the total yield of these interconnected μ-disk LEDs to be the same as the conventional broad-area LEDs. The present method of utilizing interconnected μ-disk LEDs for improving the brightness of LEDs is applicable to other semiconductor LEDs as well as polymer and organic LEDs.