The Improvement of GaN LED light extraction
| Autor: | Huang, Chuan Lee, 李煌川 |
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| Rok vydání: | 2011 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 100 In this thesis, we propose a method to increasing of LED light extraction by using high temperature wet etcher of phosphoric acid. In this method, we change geometric figure of LED chip. It decreased the reflection when the light met the sidewall of chip. The reflection occurred will increased possibility of light absorption. This technology was achieved by deposition SiO2 on sapphire using by plasma enhanced chemical vapor deposition (PECVD) and making the laser cut by laser scribe. The SiO2 was adopted the block layer and then etched in the mixture of high temperature phosphoric acid and sulfuric acid. The efficiency of sidewall etched profile on light extraction is shown in this thesis. There are three conditions of this study. The first was the changing concentrations of solution with fixed operation temperature and process time. Second was changing the operation temperature with fixed concentration of solution and process time. Third was changing the process time with fixed concentration of solution and process temperature. The results are verified by SWE width (μm), luminous intensity and SEM observation about laser scribe shape and epi layer sidewall profile. Base on the optical and the electrical characterization data, the method propsed in this thesis may increase the luminous intensity of LED through the light extraction efficiency. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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