Enhanced Light Output of GaN-Based Vertical-Structured Light-Emitting Diodes With Two-Step Surface Roughening Using KrF Laser and Chemical Wet Etching
| Autor: | Po-Hong Wang, Tron-Min Chen, Der-Ming Kuo, Shui-Jinn Wang, Wei-Chi Lee, Pei-Ren Wang, Kai-Ming Uang |
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| Rok vydání: | 2010 |
| Předmět: |
Materials science
Excimer laser business.industry medicine.medical_treatment Gallium nitride Surface finish Laser Isotropic etching Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials law.invention chemistry.chemical_compound Optics chemistry Etching (microfabrication) law Surface roughness medicine Optoelectronics Electrical and Electronic Engineering business Structured light |
| Zdroj: | IEEE Photonics Technology Letters. 22:1318-1320 |
| ISSN: | 1941-0174 1041-1135 |
| DOI: | 10.1109/lpt.2010.2055047 |
| Popis: | A two-step roughening process that uses a KrF excimer laser and KOH chemical etching for the n-GaN layer surface of vertically structured GaN-based light-emitting diodes (VLEDs) to yield circular protrusions with hexagonal cones atop for light extraction enhancement is demonstrated. A possible mechanism of the formation of the circular protrusions commenced by laser irradiation with nonuniform etching rates at sites with various dislocation densities was investigated. An improvement in light output power of about 95% at 350-750 mA compared to that of flat VLEDs was obtained for the two-step roughened VLEDs, which is attributed to the increase in surface emission area and dimensions of roughness, and, in particular, the decrease in the n-GaN layer thickness. |
| Databáze: | OpenAIRE |
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