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http://dx.doi.org/10.3807/KJOP.2011.22.1.053

A Study of the Upper Layer for Improvement of the Extraction Efficiency in LED  

Choi, Chul-Hyun (Optics and Photonics Elite Research Academy (OPERA), School of Information and Communication Engineering, INHA University)
Lee, Dong-Jin (Optics and Photonics Elite Research Academy (OPERA), School of Information and Communication Engineering, INHA University)
Yim, Hae-Dong (Optics and Photonics Elite Research Academy (OPERA), School of Information and Communication Engineering, INHA University)
Kim, Bo-Soon (Optics and Photonics Elite Research Academy (OPERA), School of Information and Communication Engineering, INHA University)
Sung, Jun-Ho (Optics and Photonics Elite Research Academy (OPERA), School of Information and Communication Engineering, INHA University)
Lee, Min-Woo (Optics and Photonics Elite Research Academy (OPERA), School of Information and Communication Engineering, INHA University)
O, Beom-Hoan (Optics and Photonics Elite Research Academy (OPERA), School of Information and Communication Engineering, INHA University)
Publication Information
Korean Journal of Optics and Photonics / v.22, no.1, 2011 , pp. 53-57 More about this Journal
Abstract
In this paper, we improved the light extraction efficiency by considering an additional upper layer on the top surface of a conventional LED. We simulated the LED's light emission as functions of the thickness and the refractive index of the upper layer, and analyzed how the condition improved the light efficiency. When the refractive index's range was from 1.05 to 1.40, the LED emission increased. For that case, the emission also increased as the thickness increased. We experimentally showed that the light extraction efficiency was improved about 22% by forming the upper layer on the top surface of an LED using material with refractive index 1.30 at 589.3 nm. It is expected that forming the upper layer on an LED can easily improve the extraction efficiency.
Keywords
LED; Extraction efficiency; Refractive index;
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