The efficiency of conventional quantum well light-emitting diodes(LEDs) decreases drastically with reducing areal size. Here we show that such a critical size scaling issue of LEDs can be addressed by utilizing N-pola...The efficiency of conventional quantum well light-emitting diodes(LEDs) decreases drastically with reducing areal size. Here we show that such a critical size scaling issue of LEDs can be addressed by utilizing N-polar In Ga N nanowires. We studied the epitaxy and performance characteristics of N-polar In Ga N nanowire LEDs grown on sapphire substrate by plasma-assisted molecular beam epitaxy. A maximum external quantum efficiency-11% was measured for LEDs with lateral dimensions as small as 750 nm directly on wafer without any packaging. The effect of electron overflow and Auger recombination on the device performance is also studied. This work provides a viable approach for achieving high-efficiency nano and micro LEDs that were not previously possible.展开更多
AlGaN nanocrystals have emerged as the building blocks of future optoelectronic devices operating in the ultraviolet(UV) spectral range. In this article, we describe the design and performance characteristics of AlGaN...AlGaN nanocrystals have emerged as the building blocks of future optoelectronic devices operating in the ultraviolet(UV) spectral range. In this article, we describe the design and performance characteristics of AlGaN nanocrystal UV light-emitting diodes(LEDs) and surface-emitting UV laser diodes. The selective-area epitaxy and structural, optical, and electrical properties of AlGaN nanocrystals are presented. The recent experimental demonstrations of AlGaN nanocrystal LEDs and laser diodes are also discussed.展开更多
文摘The efficiency of conventional quantum well light-emitting diodes(LEDs) decreases drastically with reducing areal size. Here we show that such a critical size scaling issue of LEDs can be addressed by utilizing N-polar In Ga N nanowires. We studied the epitaxy and performance characteristics of N-polar In Ga N nanowire LEDs grown on sapphire substrate by plasma-assisted molecular beam epitaxy. A maximum external quantum efficiency-11% was measured for LEDs with lateral dimensions as small as 750 nm directly on wafer without any packaging. The effect of electron overflow and Auger recombination on the device performance is also studied. This work provides a viable approach for achieving high-efficiency nano and micro LEDs that were not previously possible.
基金Army Research Office(ARO)(W911NF-17-1-0109)National Science Foundation(NSF)(DMR-1807984)
文摘AlGaN nanocrystals have emerged as the building blocks of future optoelectronic devices operating in the ultraviolet(UV) spectral range. In this article, we describe the design and performance characteristics of AlGaN nanocrystal UV light-emitting diodes(LEDs) and surface-emitting UV laser diodes. The selective-area epitaxy and structural, optical, and electrical properties of AlGaN nanocrystals are presented. The recent experimental demonstrations of AlGaN nanocrystal LEDs and laser diodes are also discussed.
