Efficiency Improvement of 630 nm AlGaInP Light-Emitting Diodes based on AlGaAs Bottom Window

Lee, Hyung Joo; Kim, Young Jin; Kim, Seong Un; Jo, Ju Ung; Lee, Choong Hun; Kim, Jae-Hoon; Ahn, Su Chang

doi:10.7567/jjap.52.102101

Cited by 8 publications

(6 citation statements)

References 20 publications

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“…The primary epistructure of red LED wafers grown on GaAs substrate is composed of a bottom distributed Bragg reflector (DBR), an AlGaInP MQW sandwiched between two AlInP cladding layers and a GaP window layer. The photon energy of red light is greater than the energy bandgap of the GaAs epilayer, thus the bottom DBRs reflect the downward-emitting photons towards the top surface to avoid substrate absorption [22]. On the other hand, as shown in Fig.…”

Section: Methodsmentioning

confidence: 99%

Underwater Optical Wireless Communications With InGaN LEDs Grown With an Asymmetric Multiple Quantum Well for Light Emission or Detection

Tsai

Wang

et al. 2022

IEEE Photonics J.

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InGaN light-emitting diodes (LEDs) grown with an asymmetric multiple quantum well (MQW) are proposed for use in an optical link with an avalanche photodiode (APD) based receiver. In contrast to the high photoresponse of red AlGaInP LEDs in APDs, the proposed blue LEDs provide improved light output and enhanced system bandwidth for directed line-of-sight optical links passing through a 100-cm-long water tank. This improvement is due to the nonuniform carrier distribution within the InGaN MQWs being mitigated by using a thin GaN barrier near the n-GaN to facilitate hole transport capacity. In addition, bandwidth degradation resulting from APD module saturation can also be avoided by using these blue LEDs, successfully establishing a 300 Mbit/s LED-based underwater data link. The proposed InGaN LEDs (zero bias) under illumination exhibit a peak responsivity of 0.133 at λ = 370 nm, an ultraviolet (UV)-to-visible rejection ratio of 4849 and a 3-dB cut-off frequency of 33.3 MHz. Using violet UV laser diodes and the proposed LEDs respectively as the optical transmitter and receiver, an underwater optical link (L = 100 cm) with a data transmission rate of up to 130 Mbit/s and a bit error rate of 4.2 × 10 −9 is also demonstrated.

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Section: Methodsmentioning

confidence: 99%

Underwater Optical Wireless Communications With InGaN LEDs Grown With an Asymmetric Multiple Quantum Well for Light Emission or Detection

Tsai

Wang

et al. 2022

IEEE Photonics J.

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“…The total internal reflection (TIR) problem leads to only few emitted photons in a narrow escape cone from the active regions; approximately 10% of the light can be extracted from the LED’s surface; approximately 90% of the light is trapped inside the LED 4 and is transformed into heat, which drastically degrades the LED’s performance after long-term operation. Therefore, one of the most crucial issues in AlGaInP-based LED research is increasing the number of photons that escape the active region 5 – 9 . Several efficient methods have been proposed and demonstrated to increase light extraction efficiency (LEE), such as the use of simple random surface roughness structures 10 , photonic crystal structures 11 , graded reflective index materials 12 , 13 , and embedded (or self-assembled) nanostructures 14 – 16 .…”

Section: Introductionmentioning

confidence: 99%

AlGaInP Red LEDs with Hollow Hemispherical Polystyrene Arrays

Cheng

Huang

Chen

et al. 2018

Sci Rep

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A hollow hemispherical polystyrene (HHPS) was fabricated to reduce total internal reflection in AlGaInP-based LEDs. At an injection current of 350 mA, the external quantum efficiencies of LED-I, LED-II, LED-III, and LED-IV are 20.92%, 24.65%, 27.28%, and 33.77% and the wall-plug efficiencies are 17.11%, 20%, 22.5%, and 27.33%, respectively. The enhanced performance is attributed to the light output power enhancement through the surface roughness, microlens-liked PS hemisphere, and scatter-liked HHPS array. In this paper, the rigorous coupled wave analysis (RCWA) numerical method was also conducted to demonstrate the HHPS array effectively enlarge the effective light cone.

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“…Some studies have also shown that the efficiency of optical device could be increased by inserting a distribution Bragg reflector (DBR), consisting of n-AlAs and n-(Al 0.5 Ga 0.5 )As, between the device and absorbing substrate [8]. Elsewhere, AlGaAs having a rough 150 μm thickness was used as the transparent substrate in order to fabricate higher efficiency optical devices [9].…”

Section: Introductionmentioning

confidence: 99%

Fabrication and Characteristics of High Quality AlGaAs Film Grown on Al2O3 Substrate

Lee¹,

Cho²,

Kim³

et al. 2014

IOSRJEN

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In this work, the characteristics of AlGaAs film grown on transparent Al 2 O 3 substrate are investigated. AlGaAs films having various Al compositions were fabricated on the GaAs buffer layer of an Al 2 O 3 substrate using metal organic chemical vapor deposition. It was found that the crystal quality and surface roughness of the AlGaAs film was gradually improved by increasing the Al composition. The relatively improved surface and crystallizations were observed at AlGaAs film having an Al composition of 80%. A marked decrease in the d-spacing between the AlGaAs plane and Al 2 O 3 substrate was clearly observed under the same condition. From these results, the high-quality AlGaAs film on the Al 2 O 3 substrate was attributed to an increase in the substitutional effect of Al for Ga caused by increasing the Al composition.

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Efficiency Improvement of 630 nm AlGaInP Light-Emitting Diodes based on AlGaAs Bottom Window

Cited by 8 publications

References 20 publications

Underwater Optical Wireless Communications With InGaN LEDs Grown With an Asymmetric Multiple Quantum Well for Light Emission or Detection

Underwater Optical Wireless Communications With InGaN LEDs Grown With an Asymmetric Multiple Quantum Well for Light Emission or Detection

AlGaInP Red LEDs with Hollow Hemispherical Polystyrene Arrays

Fabrication and Characteristics of High Quality AlGaAs Film Grown on Al2O3 Substrate

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