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Air-ring microstructure arrays for enhanced light extraction from a face-up light-emitting diode.
Hyun Kyu Kim1, Young Jae Park, Ji Hye Kang
1School of Semiconductor and Chemical Engineering, Semiconductor Physics Research Center, Chonbuk National University, Jeonju, South Korea.
Optics Letters
|May 2, 2013
Summary
A novel light-emitting diode (LED) design using prism-shaped-air-ring microstructures (PSAMs) enhances light extraction efficiency. This PSAM-LED design offers a 10% radiometric power boost compared to traditional patterned sapphire substrate LEDs.
Area of Science:
- Optoelectronics
- Solid-state lighting
- Photonics
Background:
- Traditional face-up LEDs on patterned sapphire substrate (PSS) suffer from photon loss due to internal reflection and absorption.
- Enhancing light extraction efficiency is crucial for improving LED performance and reducing energy consumption.
Purpose of the Study:
- To demonstrate a new light-emitting diode (LED) design utilizing prism-shaped-air-ring microstructures (PSAMs) on a flat sapphire substrate.
- To evaluate the effectiveness of PSAMs in enhancing light extraction efficiency compared to conventional PSS-LEDs.
Main Methods:
- Fabrication of PSAMs on a flat sapphire substrate for LED construction.
- Experimental comparison of radiometric power and far-field angle between PSAM-LEDs and PSS-LEDs.
- Testing under a consistent injection current of 20 mA.
Main Results:
- The PSAM-LED design effectively deflects emitted photons towards the top of the chip, minimizing absorption losses.
- A radiometric power enhancement of up to 10% was observed in PSAM-LEDs compared to PSS-LEDs.
- The PSAM-LED exhibited a reduced far-field emission angle of 129°.
Conclusions:
- PSAMs offer a viable alternative to PSS for improving light extraction efficiency in LEDs.
- The proposed PSAM-LED design leads to significant performance gains in radiometric power.
- This innovative approach contributes to the development of more efficient solid-state lighting technologies.
