Browsing by Author "Lin, C. F."

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Enhancement of light output power of GaN-based light-emitting diodes using a SiO(2) nano-scale structure on a p-GaN surface
(2010-06-01)
Huang, H. W.
;
Lai, F. I.
;
Huang, J. K.
;
Lin, C. H.
;
Lee, K. Y.
GaN (gallium nitride)-based light-emitting diodes (LEDs) with a nano-scale SiO(2) structure between a transparent indium-tin oxide (ITO) layer and p-GaN were fabricated. The forward voltage at 20 mA for a GaN-based LED with a SiO(2) nano-scale structure was slightly higher than that of a conventional GaN-based LED because the total area of the p-type metal contact between the transparent ITO layer and p-GaN was smaller. However, the light output power for the GaN-based LED with a nano-scale structured SiO(2) at 20 mA was 24% higher than that for a conventional GaN-based LED structure. This increase in the light output power is mostly attributed to the scattering of light from the SiO(2) photonic quasi-crystal (PQC) layer.
Enhancement of light output power of GaN-based light-emitting diodes using a SiO2 nano-scale structure on a p-GaN surface
(2010-06-01)
Huang, H. W.
;
Lai, F. I.
;
Huang, J. K.
;
Lin, C. H.
;
Lee, K. Y.
GaN (gallium nitride)-based light-emitting diodes (LEDs) with a nano-scale SiO2 structure between a transparent indium-tin oxide (ITO) layer and p-GaN were fabricated. The forward voltage at 20 mA for a GaN-based LED with a SiO2 nano-scale structure was slightly higher than that of a conventional GaN-based LED because the total area of the p-type metal contact between the transparent ITO layer and p-GaN was smaller. However, the light output power for the GaN-based LED with a nano-scale structured SiO2 at 20 mA was 24% higher than that for a conventional GaN-based LED structure. This increase in the light output power is mostly attributed to the scattering of light from the SiO2 photonic quasi-crystal (PQC) layer.
Fabrication of InGaN/GaN nanorod light-emitting diodes with self-assembled Ni metal islands
(2007-11-07)
Chiu, C. H.
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Lu, T. C.
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Huang, H. W.
;
Lai, C. F.
;
Kao, C. C.
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.
Investigation of GaN-based light emitting diodes with nano-hole patterned sapphire substrate (NHPSS) by nano-imprint lithography
(2009-08-25)
Huang, H. W.
;
Lin, C. H.
;
Huang, J. K.
;
Lee, K. Y.
;
Lin, C. F.
In this paper, gallium-nitride (GaN)-based light-emitting diodes (LEDs) with nano-hole patterned sapphire (NHPSS) by nano-imprint lithography are fabricated and investigated. At an injection current of 20mA, the LED with NHPSS increased the light output power of the InGaN/GaN multiple quantum well LEDs by a factor of 1.33, and the wall-plug efficiency is 30% higher at 20mA indicating that the LED with NHPSS had larger light extraction efficiency. In addition, by examining the radiation patterns, the LED with NHPSS shows stronger light extraction with a wider view angle. These results offer promising potential to enhance the light output powers of commercial light-emitting devices using the technique of nano-imprint lithography. (C) 2009 Elsevier B.V. All rights reserved.
Light Extraction Efficiency Enhancement of GaN-Based Light Emitting Diodes on n-GaN Layer Using a SiO(2) Photonic Quasi-Crystal Overgrowth
(2010-10-01)
Huang, H. W.
;
Lee, K. Y.
;
Huang, J. K.
;
Lin, C. H.
;
Lin, C. F.
In this paper, GaN-based LEDs with a SiO(2) photonic quasi-crystal (PQC) pattern on an n-GaN layer by nano-imprint lithography (NIL) are fabricated and investigated. At a driving current of 20 mA on Transistor Outline (TO)-can package, the better light output power of LED III (d = 1.2 mu m) was enhanced by a factor of 1.20. After 1000 h life test (55 degrees C/50 mA) condition, Normalized output power of LED with a SiO(2) PQC pattern (LED III (d = 1.2 mu m)) on an n-GaN layer only decreased by 5%. This results offer promising potential to enhance the light output power of commercial light-emitting devices using the technique of nano-imprint lithography.
Light-Output-Power Enhancement of GaN-Based Light-Emitting Diodes on an n-GaN Layer Using a SiO(2) Photonic Quasi-Crystal Overgrowth
(2010-06-01)
Huang, H. W.
;
Huang, J. K.
;
Lee, K. Y.
;
Lin, C. F.
;
Kuo, H. C.
GaN-based LEDs with a SiO(2) oxide PQC pattern on an n-GaN layer by nanoimprint lithography are fabricated and investigated. At a driving current of 20 mA on a Transistor-Outline-can package, the light output power of LED III (d = 1.2 mu m) was enhanced by a factor of 1.20. The internal-quantum-efficiency result offers promising potential to enhance the light output power of commercial light-emitting devices with a SiO(2) oxide PQC structure on an n-GaN layer.
Light-Output-Power Enhancement of GaN-Based Light-Emitting Diodes on an n-GaN Layer Using a SiO2 Photonic Quasi-Crystal Overgrowth
(2010-06-01)
Huang, H. W.
;
Huang, J. K.
;
Lee, K. Y.
;
Lin, C. F.
;
Kuo, H. C.
GaN-based LEDs with a SiO2 oxide PQC pattern on an n-GaN layer by nanoimprint lithography are fabricated and investigated. At a driving current of 20 mA on a Transistor-Outline-can package, the light output power of LED III (d = 1.2 mu m) was enhanced by a factor of 1.20. The internal-quantum-efficiency result offers promising potential to enhance the light output power of commercial light-emitting devices with a SiO2 oxide PQC structure on an n-GaN layer.
Optical properties of In0.3Ga0.7N/GaN green emission nanorods fabricated by plasma etching
(2007-08-22)
Chiu, C. H.
;
Lo, M. H.
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Lai, C. F.
;
Lu, T. C.
;
Huang, H. W.
In this study, we have fabricated In0.3Ga0.7N/GaN green emission nanorods and demonstrated optical enhancement by photoluminescence (PL) measurements. An enhancement factor of 3.5 and an emission peak blue-shift of 6.6 nm were observed at 300 K for the green emission nanorods structure in comparison to the as-grown flat surface structure. The blue-shift phenomenon from the nanorod structure could be caused by a partial reduction of the internal piezoelectric field. However, the similar carrier decay time for the green emission nanorod structure and the as-grown flat surface structure observed in low-temperature time-resolved PL measurements indicates that the dominant optical enhancement mechanism of the green emission nanorod structure could be mainly resulting from the large emission surface areas and the multiple scattering paths between the nanorods.