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Optical performance of top-down fabricated InGaN/GaN nanorod light emitting diode arrays

Optics Express

Li, Qiming L.; Crawford, Mary H.; Koleske, Daniel K.; Figiel, J.J.; Cross, Karen C.; Wang, George T.

Vertically aligned InGaN/GaN nanorod light emitting diode (LED) arrays were created from planar LED structures using a new top-down fabrication technique consisting of a plasma etch followed by an anisotropic wet etch. The wet etch results in straight, smooth, well-faceted nanorods with controllable diameters and removes the plasma etch damage. 94% of the nanorod LEDs are dislocation-free and a reduced quantum confined Stark effect is observed due to reduced piezoelectric fields. Despite these advantages, the IQE of the nanorod LEDs measured by photoluminescence is comparable to the planar LED, perhaps due to inefficient thermal transport and enhanced nonradiative surface recombination.

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TYPE Journal Article YEAR 2011
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Carrier recombination mechanisms and efficiency droop in GaInN/GaN light-emitting diodes

Applied Physics Letters

Crawford, Mary H.; Koleske, Daniel K.

In this work, we model the carrier recombination mechanisms in GaInN/GaN light-emitting diodes as R=An+Bn2+Cn3+f(n), where f(n) represents carrier leakage out of the active region. The term f(n) is expanded into a power series and shown to have higher-than-third-order contributions to the recombination. The total third-order nonradiative coefficient (which may include an f(n) leakage contribution and an Auger contribution) is found to be 8×10-29 cm6 s-1. Finally, comparison of the theoretical ABC+f(n) model with experimental data shows that a good fit requires the inclusion of the f(n) term.

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TYPE Journal Article YEAR 2010
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Results 176–200 of 251
Results 176–200 of 251