The Investigation of Opto-Electronic Characteristics in Yellow-Green AlGaInP Light-Emitting Diodes

• Main Authors: Li-Chang Chou, 鄒李昌
• Other Authors: Tzer-En Nee
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/92528020887374535195

碩士 === 長庚大學 === 半導體研究所 === 90 === Current spreading effect on luminescence distribution in AlGaInP light emitting diodes (LEDs) with selectively wet oxidized AlAs/AlGaAs distributed Bragg reflector (DBR) structures has been systematically investigated. The measured brightness per unit area of an oxidized LED is up to 4.18 times greater than that of an as-grown one at the same current density. This significant improvement in the emission characteristics with the Al-based native oxides is considered to be the result of the current spreading effect. With an increase in the lateral oxidized depth, the centralized phenomena for the near-field patterns are also profound. These are attributed to the confinement of the current spreading between the contact and the un-oxidized active region. It is also found that the centralized carriers contribute to the enhancement of the external quantum efficiency per unit area up to factor of 58.6. As a result, optimal control the oxidized lateral depth in DBR layer is thus a potential to approach for improving the LED brightness.