Study of Light Output characteristics of InGaN-based Micro-Hole Array Light-Emitting Diodes

• Main Authors: Jui Yi Chu, 朱瑞溢
• Other Authors: Hao-chung Kuo
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/32510942736399674339

碩士 === 國立交通大學 === 光電工程系所 === 93 === GaN-based micro-hole array LEDs, with hole diameter= 3、7、11 and 15 μm, were fabricated with self-aligned technique. The electrical and light output properties of the micro-hole array LEDs are studied and compared that of the conventional broad-area (BA) LEDs. The forward bias voltage, VF, of the GaN-based micro-hole array LEDs at a driving current of 20 mA increases with d and slightly exceeds that of the conventional BA LEDs. The light output from the micro-hole array LEDs was over 36% grater than that from conventional LEDs with the same device areas. Besides, the enhancement factor of light output from the experimental data decreases as γ increases above 6% (d > 7 µm) and no enhancement is observed from the micro-hole array LEDs at γ > 28%. The optimal design for the GaN-based micro-hole array LEDs are achieved in this work by the experiment and simulation methods. Furthermore, the optimal design of micro-hole array is used on the GaN-based large-area LEDs. Two kinds of electric conductive material of ITO and Ni/Au are used as the transparent contact layer to the GaN-based large-area micro-hole array LEDs. The results showed that the transparent contact layer of ITO not only decreased the device resistance but also extend the roll-over current. From the emission far-field pattern of LEDs, we found that the micro-hole array on LEDs have little influence on the far field angle. At FWHM, the far field angles are in the range of 75° ~ 80°.