Stress engineering for reducing the injection current induced blue shift in InGaN-based red light-emitting diodes

Red LEDs with a small blue shift are fabricated by using a stress engineering strategy through the growth of the pre-stained InGaN layer and dual-wavelength QWs on a cone-shape patterned sapphire substrate.

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Investigation of a Separated Short-Wavelength Peak in InGaN Red Light-Emitting Diodes

Crystals ◽

10.3390/cryst11091123 ◽

2021 ◽

Vol 11 (9) ◽

pp. 1123

Author(s):

Pavel Kirilenko ◽

Zhe Zhuang ◽

Daisuke Iida ◽

Martin Velazquez-Rizo ◽

Kazuhiro Ohkawa

Keyword(s):

Quantum Wells ◽

Short Wavelength ◽

Light Emitting Diodes ◽

Red Light ◽

Blue Shift ◽

Light Emitting ◽

Peak Emission Wavelength ◽

Wavelength Emission ◽

Main Emission Peak ◽

Red Leds

We fabricated indium gallium nitride (InGaN) red light-emitting diodes (LEDs) with a peak emission wavelength of 649 nm and investigated their electroluminescence (EL) properties. An additional separated peak in the EL spectrum of the red LEDs at 20 mA was observed at 465 nm. This additional peak also exhibits a blue-shift with increasing currents as does the main emission peak. Using high-resolution microscopy, we observed many point-like emission spots in the EL emission images at the currents below 1 mA. However, these emission spots cannot be identified at currents above 5 mA because the red emission from quantum wells (QWs) is much stronger than that emitted by these spots. Finally, we demonstrate that these emission spots are related to the defects generated in red QWs. The measured In content was lower at the vicinity of the defects, which was regarded as the reason for separated short-wavelength emission in red InGaN LEDs.

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Investigation and Comparison of the GaN-Based Light-Emitting Diodes Grown on High Aspect Ratio Nano-Cone and General Micro-Cone Patterned Sapphire Substrate

Journal of Display Technology ◽

10.1109/jdt.2013.2270276 ◽

2013 ◽

Vol 9 (12) ◽

pp. 947-952 ◽

Cited By ~ 11

Author(s):

Jhih-Kai Huang ◽

Da-Wei Lin ◽

Min-Hsiung Shih ◽

Kang-Yuan Lee ◽

Jyun-Rong Chen ◽

...

Keyword(s):

Aspect Ratio ◽

Sapphire Substrate ◽

High Aspect Ratio ◽

Light Emitting Diodes ◽

Patterned Sapphire Substrate ◽

Light Emitting

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InGaN-Based Near-Ultraviolet and Blue-Light-Emitting Diodes with High External Quantum Efficiency Using a Patterned Sapphire Substrate and a Mesh Electrode

Japanese Journal of Applied Physics ◽

10.1143/jjap.41.l1431 ◽

2002 ◽

Vol 41 (Part 2, No. 12B) ◽

pp. L1431-L1433 ◽

Cited By ~ 296

Author(s):

Motokazu Yamada ◽

Tomotsugu Mitani ◽

Yukio Narukawa ◽

Shuji Shioji ◽

Isamu Niki ◽

...

Keyword(s):

Blue Light ◽

Quantum Efficiency ◽

Sapphire Substrate ◽

External Quantum Efficiency ◽

Light Emitting Diodes ◽

Patterned Sapphire Substrate ◽

Light Emitting ◽

Near Ultraviolet

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Suppressing the Initial Growth of Sidewall GaN by Modifying Micron-Sized Patterned Sapphire Substrate with H3PO4-Based Etchant

Micromachines ◽

10.3390/mi9120622 ◽

2018 ◽

Vol 9 (12) ◽

pp. 622 ◽

Cited By ~ 3

Author(s):

Wen-Yang Hsu ◽

Yuan-Chi Lian ◽

Pei-Yu Wu ◽

Wei-Min Yong ◽

Jinn-Kong Sheu ◽

...

Keyword(s):

Sapphire Substrate ◽

Light Emitting Diodes ◽

Ex Situ ◽

Initial Growth ◽

Patterned Sapphire Substrate ◽

Light Emitting ◽

Sapphire Substrates ◽

Patterned Sapphire Substrates

Micron-sized patterned sapphire substrates (PSS) are used to improve the performance of GaN-based light-emitting diodes (LEDs). However, the growth of GaN is initiated not only from the bottom c-plane but also from the sidewall of the micron-sized patterns. Therefore, the coalescence of these GaN crystals creates irregular voids. In this study, two kinds of nucleation layers (NL)—ex-situ AlN NL and in-situ GaN NL—were used, and the growth of sidewall GaN was successfully suppressed in both systems by modifying the micron-sized PSS surface.

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