Enhanced light output power of InGaN-based amber LEDs by strain-compensating AlN/AlGaN barriers

Iida, Daisuke; Shen, Linyong; Hirahara, Sota; Niwa, Kazumasa; Kamiyama, Satoshi; Ohkawa, Kazuhiro

doi:10.1016/j.jcrysgro.2016.05.023

Cited by 57 publications

(60 citation statements)

References 28 publications

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“…All of these are fundamentally related to an increase in the indium composition in the active region. One possible solution to overcome the green-gap could be strain engineering that employs a strain compensation/relaxation layer, e.g., superlattice layers (SLs), an AlGaN interlayer, a GaInN underlayer, and graded indium composition across multiple quantum wells (MQWs) in the active region [16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Enhanced Device Performance of GaInN-Based Green Light-Emitting Diode with Sputtered AlN Buffer Layer

et al. 2019

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In this study, we compared the device performance of GaInN-based green LEDs grown on c-plane sapphire substrates with a conventional low temperature GaN buffer layer to those with a sputtered-AlN buffer layer. The light output power and leakage current characteristics were significantly improved by just replacing the buffer layer with a sputtered-AlN layer. To understand the origin of the improvement in performance, the electrical and optical properties were compared by means of electro-reflectance spectroscopy, I–V curves, electroluminescence spectra, L–I curves, and internal quantum efficiencies. From the analysis of the results, we concluded that the improvement is mainly due to the mitigation of strain and reduction of the piezoelectric field in the multiple quantum wells active region.

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Section: Introductionmentioning

confidence: 99%

Enhanced Device Performance of GaInN-Based Green Light-Emitting Diode with Sputtered AlN Buffer Layer

et al. 2019

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“…One approach for higher efficiency longer wavelength InGaN LEDs that has produced record efficiencies at green gap wavelengths is the use of AlGaN interlayers in the multiple quantum well (MQW) active layer . This is most interesting in the green and red because of demonstrated record external quantum efficiencies of ≈25% at ≈550 nm and ≈2.5% at ≈608 nm.…”

Section: Challenges and Solutionsmentioning

confidence: 99%

III‐Nitride Micro‐LEDs for Efficient Emissive Displays

Wierer

Tansu

2019

Laser & Photonics Reviews

119

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Emissive displays based on light‐emitting diodes (LEDs), with high pixel density, luminance, efficiency, and large color gamut, are of great interest for applications such as watches, phones, and virtual displays. The high pixel density requirements of some emissive displays require a particular class of LEDs that are sub‐20‐micrometers in length, called micro‐LEDs. While state‐of‐the‐art emissive displays incorporate organic LEDs, an alternative is inorganic III‐nitride LEDs with potential reliability and efficiency benefits. Here we explore the performance, challenges, and prospective outcomes for III‐nitride micro‐LEDs to produce efficient emissive displays and provide insight to advance this technology. Calculations are performed to determine the operating points for the micro‐LEDs and the efficiency of the overall emissive display. It is shown that III‐nitride micro‐LEDs suffer from some of the same problems as their larger‐sized solid‐state lighting LED cousins; however, the operating conditions of micro‐LEDs can result in different challenges and research efforts. These challenges include improving efficiency at low current densities; improving the efficiency of longer wavelength (green and red) LEDs; and creating device designs that can overcome low coupling efficiency, high surface recombination, and display assembly difficulties.

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“…MQW and AlN interlayers were grown at 740°C, and GaN and AlGaN barrier layers were grown at 850°C. The higher growth temperature for barrier layers can improve the crystalline quality of MQWs [18].…”

Section: Sample Preparationmentioning

confidence: 99%

Efficiency enhancement of InGaN amber MQWs using nanopillar structures

Iida

Liu

et al. 2017

Nanophotonics

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Abstract:We have investigated the use of nanopillar structures on high indium content InGaN amber multiple quantum well (MQW) samples to enhance the emission efficiency. A significant emission enhancement was observed which can be attributed to the enhancement of internal quantum efficiency and light extraction efficiency. The size-dependent strain relaxation effect was characterized by photoluminescence, Raman spectroscopy and timeresolved photoluminescence measurements. In addition, the light extraction efficiency of different MQW samples was studied by finite-different time-domain simulations. Compared to the as-grown sample, the nanopillar amber MQW sample with a diameter of 300 nm has demonstrated an emission enhancement by a factor of 23.8.

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Enhanced light output power of InGaN-based amber LEDs by strain-compensating AlN/AlGaN barriers

Cited by 57 publications

References 28 publications

Enhanced Device Performance of GaInN-Based Green Light-Emitting Diode with Sputtered AlN Buffer Layer

Enhanced Device Performance of GaInN-Based Green Light-Emitting Diode with Sputtered AlN Buffer Layer

III‐Nitride Micro‐LEDs for Efficient Emissive Displays

Efficiency enhancement of InGaN amber MQWs using nanopillar structures

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