Improvement of InGaN/GaN light emitting diode performance with a nano-roughened p-GaN surface by excimer laser-irradiation

Huang, H. W.; Kao, Chih−Chiang; Chu, Jhih‐Wei; Liang, W.; Kuo, Hao‐Chung; Wang, S.C.; Yu, C. C.

doi:10.1016/j.matchemphys.2005.11.013

Cited by 16 publications

(7 citation statements)

References 14 publications

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“…A more controlled approach is to produce a periodic arrangement of surface structures, a ''photonic crystal'', at the surface that prevents total internal reflection. For example, an array of GaN nano-pyramids produced by etching [28,57] produces a significant increase in light extraction efficiency.…”

Section: Led Devicesmentioning

confidence: 99%

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Use of Nanostructures for High Brightness Light-Emitting Diodes

Stringfellow

2011

Energy Efficiency and Renewable Energy Through Nanotechnology

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Light-emitting diodes or LEDs are expected to play a major role in efforts to utilize less energy for lighting applications due to their high efficiency, long operating life, and other ''green'' characteristics. The history of LEDs began in the 1960s. Since that time, the performance has increased exponentially while the cost has decreased dramatically. LEDs dominate the market for monochromatic displays and indicators, and are slated to provide an increasing share of the white light market. During the last decade, advances in efficiency have been obtained partly as a result of the use of nanotechnology. LEDs and lasers provided some of the first applications for quantum-well structures with nm dimensions. Future advances will almost certainly be linked to advances in the use of quantum wire and quantum dot structures. They appear to offer attractive new alternatives for single-junction white light generation. The use of self-assembled structures also offers the promise of allowing the fabrication of high efficiency devices in highly defected materials, such as those grown on less expensive substrates. This chapter reviews the basic aspects of LED devices and materials, with a focus on the AlGaInP system for red and yellow emitters and AlGaInN for blue, green, and white emitters, all grown by the organometallic vapor phase epitaxial technique. The focus is on the present and future use of nanotechnology for lighting applications.

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Section: Led Devicesmentioning

confidence: 99%

“…Shaping of the individual diodes is also used to enhance light extraction [36]. More recently, the use of nanotechnology has been developed to produce surfaces structures to enhance the light extraction efficiency [28].…”

Section: Introductionmentioning

confidence: 99%

Use of Nanostructures for High Brightness Light-Emitting Diodes

Stringfellow

2011

Energy Efficiency and Renewable Energy Through Nanotechnology

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“…In addition, achieving the small dimensions of scattering objects through photolithography is difficult because of the short wavelength of nitride-based LEDs. Studies [ 24 – 26 ] have reported that a textured GaN surface can be used to increase the critical angle to enhance the LEE. However, surface texturing of GaN-based LEDs is impeded by the thin p-GaN and the sensitivity of p-GaN to plasma damage and electrical deterioration.…”

Section: Introductionmentioning

confidence: 99%

Preparation of a Periodic Polystyrene Nanosphere Array Using the Dip-Drop Method with Post-deposition Etching and Its Application of Improving Light Extraction Efficiency of InGaN/GaN LEDs

Lei

Yang

et al. 2018

Nanoscale Res Lett

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In this study, we synthesized a periodic polystyrene nanosphere (PS NS) array using the dip-drop method with post-deposition etching to improve the light extraction efficiency (LEE) of InGaN/GaN light-emitting diodes (LEDs). The dip-drop method has advantages such as simple procedure, inexpensive equipment, room temperature deposition, and easy implementation in LEDs. The arrangement of PS NSs on an indium-tin-oxide (ITO)-coated glass substrate depends on the average dip-drop speed and the concentration of the PS NS suspension. The periodic PS NS array can modulate the in-plane wave vector of emission light from a semiconductor to free space and thus increase the escape probability. The calculated and experimental results indicated that the light output intensity of the InGaN/GaN LEDs can be improved by using the periodic PS NS array as a window layer; this array comprises PS NSs with a diameter of 100 nm separated with periods of 100 and 100 nm in the x and y directions. Because of the improved LEE, the InGaN/GaN LEDs with the optimal PS NS array window layers exhibited a 38% increase in light output intensity compared with the conventional InGaN/GaN LEDs under 20-mA driving current.

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“…With a vertical-type LED, the n-(or undoped) GaN surface can be roughened or patterned, after the substrate separation process [27][28][29][30][31][32]. While the roughening of the surface can be processed using several different methods, including wetetching [12-14, 27, 28], dry-etching [15][16][17]29], laser treatment [18,19,31], or control over the growth conditions [20,21,32], the wet-etching is commonly used, due to its low cost and simple experimental procedure. A KOH based-solution is one of the more widely used etchants for the wet-etching technique [33].…”

Section: Introductionmentioning

confidence: 99%

Light output improvement of 10 W operated vertical LEDs via surface roughening using a commercialized developer

Jeong

Park

Jung

et al. 2015

J Mater Sci: Mater Electron

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We report improvement of improvement effectiveness of the light extraction efficiency of 10 W operated InGaN-based vertical light-emitting diodes via n-GaN surface roughening, using a commercial photoresist (PR) developer as an etching solution, which was compared with a conventional KOH-based solution. With the conventional KOH-based solution for n-GaN surface roughening, although both the depth and density of the etch pyramid initially increased with etching time, the depth eventually decreased and the density also decreased gradually, resulting in degradation in improvement effectiveness of extraction efficiency. Using the commercial PR developer for etching, however, after an initial increase in both the depth of the etch pyramid and its density, the depth and density were maintained without degradation, confirming the improvement in improvement effectiveness of extraction efficiency as well as the improvement in run to run fabrication uniformity. This may be due that with developer the GaN surface is etched only along the dislocation and is not etched over the non-defect region even as etching time goes on.

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Improvement of InGaN/GaN light emitting diode performance with a nano-roughened p-GaN surface by excimer laser-irradiation

Cited by 16 publications

References 14 publications

Use of Nanostructures for High Brightness Light-Emitting Diodes

Use of Nanostructures for High Brightness Light-Emitting Diodes

Preparation of a Periodic Polystyrene Nanosphere Array Using the Dip-Drop Method with Post-deposition Etching and Its Application of Improving Light Extraction Efficiency of InGaN/GaN LEDs

Light output improvement of 10 W operated vertical LEDs via surface roughening using a commercialized developer

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