Electrical-optical analysis of a GaN/sapphire LED chip by considering the resistivity of the current-spreading layer
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The effects of current distribution in LED chips on the electrical potential and optical light extraction efficiency are investigated by a numerical simulation. The results show that when the resistivity of the current-spreading layer is decreased there is current-crowding near the n-contact. On the other hand, when the resistivity in the current-spreading layer increases, there is current-crowding near the p-contact. When the current is crowded near the n-contact due to less resistivity of the current-spreading layer, the input power is lower because of the smaller series resistance in the chip, and the light extraction efficiency is higher since the shadowing effect of the p-contact can be avoided. For L p = 50 μm in this study, the light extraction efficiency at ρ ITO = 0.1 × 10−3 Ω·cm is 1.4 times better than that when L p = 100 μm, even though the driving voltage is raised 1.02 times.
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- Electrical-optical analysis of a GaN/sapphire LED chip by considering the resistivity of the current-spreading layer
Volume 16, Issue 2 , pp 213-215
- Cover Date
- Print ISSN
- Online ISSN
- Optical Society of Japan
- Additional Links
- light-emitting diodes
- indium tin oxide
- numerical simulation
- light extraction efficiency
- Industry Sectors
- Author Affiliations
- 1. Department of Mechanical Engineering, National Central University, Jhongli, 32001, Taiwan
- 2. Department of Mechanical Engineering, Nanya Institute of Technology, Jhongli, 32091, Taiwan
- 3. Institute of Electro-Optical Science and Engineering and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan, 70101, Taiwan
- 4. Institute of Optical Sciences, National Central University, Jhongli, 32001, Taiwan