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Miaoli, Taiwan

Liu J.-Z.,National Tsing Hua University | Liu J.-Z.,Luxtaltek Corporation | Charlton M.D.B.,University of Southampton | Lin C.-H.,Luxtaltek Corporation | And 4 more authors.
IEEE Journal of Quantum Electronics | Year: 2014

In this paper, we investigate the efficiency enhancement of blue InGaN/GaN light-emitting diodes (LEDs) by incorporating a burried air void photonic crystal (BAVPC) layer within the epitaxial structure. As compared with the conventional patterned sapphire substrate (C-PSS) LEDs and flat sapphire substrate LEDs with BAVPC, the fabricated patterned sapphire substrate (PSS) LEDs with BAVPC exhibit the lowest full-width at half-maximum of (002) and (102) diffraction peaks, the highest light output power of 20.6 mW, and the highest external quantum efficiency of 37.4%. Remarkable performance improvement in the PSS LED with BAVPC is attributed to the better epitaxial quality with threading dislocations terminated by the BAVPC and the higher scattering at interface between GaN and air-void. By positioning the BAVPC directly below the multiple quantum wells (MQWs), it would cause the reduction in the number of trapped optical modes. The methodology optically isolates the MQWs from the underlying substrate and increases the optical output power. Moreover, threading dislocations are significantly suppressed using the BAVPC with high air filling fraction of ∼50. It is well proposed that this methodology provides a promising alternative to C-PSS LEDs. © 1965-2012 IEEE. Source

Huang J.-K.,National Chiao Tung University | Liu C.-Y.,National Chiao Tung University | Chen T.-P.,National Chiao Tung University | Huang H.-W.,National Chiao Tung University | And 6 more authors.
IEEE Journal on Selected Topics in Quantum Electronics | Year: 2015

High light extraction GaN-based light-emitting diodes (LEDs) with a hybrid structure of straight nanorods located in an array of microholes have been successfully demonstrated. Via the nanoimprint lithography and photolithography techniques, high aspect-ratio light-guiding InGaN/GaN nanorods can be fabricated and regularly arranged in microholes, resulting in a great improvement of the light extraction for the GaN-based LED device. The light output power of the hybrid nanorods LED is 22.04 mW at the driving current standard of 25.4 A/cm2, an enhancement of 38.7% to the conventional GaN-based LEDs. Furthermore, with a modification of the hybrid structures' dimensions and locations, the emitted optical energy can be redistributed to obtain light-emitting devices with homogenueous optical field distributions. © 1995-2012 IEEE. Source

Luxtaltek Corporation | Date: 2014-08-06

A touch panel includes: a transparent rigid window screen having an inner surface and an outer surface that is adapted to be touched by a user; and a touch sensor module secured to the inner surface of the transparent rigid window screen for detecting at least one touch position of the users touch on the outer surface. The outer surface of the transparent rigid window screen is formed with an antireflection layer that includes a plurality of protruding pillars protruding outwardly from the outer surface and arranged to take a form of a quasicrystalline pattern having a plurality of pattern sections that are collectively ordered but not periodic.

Chanyawadee S.,University of Southampton | Lagoudakis P.G.,University of Southampton | Harley R.T.,University of Southampton | Charlton M.D.B.,University of Southampton | And 3 more authors.
Advanced Materials | Year: 2010

An efficient hybrid color-conversion light-emitting device consisting of colloidal nanocrystal quantum dots (NQDs) and a surface-patterned GaN-based LED is demonstrated (see figure). Excitation in a surface-patterned LED is efficiently transferred to NQD emitters via non-radiative energy transfer. A twofold enhancement of the NQD emission is achieved. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Huang J.-K.,National Chiao Tung University | Lin D.-W.,National Chiao Tung University | Shih M.-H.,National Chiao Tung University | Shih M.-H.,Academia Sinica, Taiwan | And 8 more authors.
IEEE/OSA Journal of Display Technology | Year: 2013

In this paper, we demonstrated the high performance GaN-based LEDs by using a high aspect ratio cone-shape nano-patterned sapphire substrate (HAR-NPSS). We utilized nano-imprint lithography (NIL) and dry-etching system to fabricate a high depth HAR-NPSS. The micro-scale patterned sapphire substrate (PSS) was also used for comparison. A great enhancement of light output was observed when GaN-based LEDs were grown on a HAR-NPSS or a PSS. The light output power of LEDs with a HAR-NPSS and LEDs with a PSS were enhanced of 49 and 38% compared to LEDs with a unpatterned sapphire substrate. The high output power of the LED with a HAR-NPSS indicated that the technology of NAR-NPSS not only can improve the crystalline quality of GaN-based LEDs but also a promising development to a NPSS. © 2013 IEEE. Source

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