We report the fabrication of InGaN/GaN nanorod light-emitting diodes (LEDs) using inductively coupled plasma reactive-ion etching (ICP-RIE) and a photo-enhanced chemical (PEC) wet oxidation process via self-assembled Ni nanomasks. An enhancement by a factor of six times in photoluminescence (PL) intensities of nanorods made with the PEC process was achieved in comparison to that of the as-grown structure. The peak wavelength observed from PL measurement showed a blue shift of 3.8 nm for the nanorods made without the PEC oxidation process and 8.6 nm for the nanorods made with the PEC oxidation process from that of the as-grown LED sample. In addition, we have demonstrated electrically pumped nanorod LEDs with the electroluminescence spectrum showing more efficiency and a 10.5 nm blue-shifted peak with respect to the as-grown LED sample.

This investigation describes the development of an InGaN/GaN light emitting diode (LED) with a nano-roughened top p-GaN surface using an Ni nano-mask and laser etching. The light output of the InGaN/GaN LED with a nano-roughened top p-GaN surface is 1.55 times that of a conventional LED, and the wall-plug efficiency is 68% higher at 20 mA. The series resistance of the InGaN/GaN LED was reduced by 32% by the increase in the contact area of the nano-roughened surface.

We demonstrate 1.1-Gb/s visible light communication (VLC) employing carrier-less amplitude and phase modulation (CAP) and a commercially available phosphorescent white light emitting diode (LED). Optical blue filtering, precompensation, and decision feedback equalization are used to compensate the frequency response of the phosphor-based white LED. Various modulation orders of CAP signals are investigated to maximize the capacity of the VLC system. The record data rate of 1.1 Gb/s with the bit error rate performance below the FEC limit of 10 −3 is successfully achieved > 23-cm air-transmission via a 220-MBaud 32-CAP signal. Index Terms-Blue filter, carrier-less amplitude and phase modulation (CAP), decision feedback equalizer, visible light communication, white light emitting diode (LED).

GaN-based vertical-cavity surface emitting laser with 3 λ cavity and hybrid mirrors, consisting of the 25 pairs AlN∕GaN dielectric Bragg reflector and the 8 pairs Ta2O5∕SiO2, was fabricated. The laser action was achieved under the optical pumping at room temperature with a threshold pumping energy density of about 53mJ∕cm2. The laser emits 448 nm blue wavelength with a linewidth of 0.25 nm and the laser beam has a degree of polarization of about 84%.

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In this paper, GaN-based LEDs with a nanoscale patterned sapphire substrate (NPSS) and a SiO2 photonic quasicrystal (PQC) structure on an n-GaN layer using nanoimprint lithography are fabricated and investigated. The light output power of LED with a NPSS and a SiO2 PQC structure on an n-GaN layer was 48% greater than that of conventional LED. Strong enhancement in output power is attributed to better epitaxial quality and higher reflectance resulted from NPSS and PQC structures. Transmission electron microscopy images reveal that threading dislocations are blocked or bended in the vicinities of NPSS layer. These results provide promising potential to increase output power for commercial light emitting devices.

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