Making distributed Bragg reflrctors on blue or green LED with optical thin film deposition
碩士 === 元智大學 === 電機工程學系 === 99 === In this thesis, we add the Distributed Bragg Reflector ( DBR ) technique and the metal mirror reflector to improve the external light output of the blue/green GaN-based light-emitting diodes. We deposit the DBR structures and metal mirror on wafer backside that succ...
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| Format: | Others |
| Language: | zh-TW |
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2011
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| Online Access: | http://ndltd.ncl.edu.tw/handle/62479923458699026259 |
| Summary: | 碩士 === 元智大學 === 電機工程學系 === 99 === In this thesis, we add the Distributed Bragg Reflector ( DBR ) technique and the metal mirror reflector to improve the external light output of the blue/green GaN-based light-emitting diodes. We deposit the DBR structures and metal mirror on wafer backside that successfully improve the light output efficiency about 8--12% for blue LEDs (8*11 mil) and green LEDs (16*16 mil) after package. The significant improvement can be attributed to the DBR structure which is highly reflective. In experiment, first we did the optical simulation to calculate the optimal reflector layer thickness and structures with the reflectivity of about 95%. After the reflector structure is defined, we use the ion-beam assisted deposition to get the highly reflective reflector on wafer backside. Finally, the result shows that the brightness of LED with DBR/metal reflector is higher than that with typical SiO2/metal reflector.
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