Enhancement of Light Output Intensity in LEDs with Patterned Substrate

• Main Authors: Han Ku, 古涵
• Other Authors: Mau-Phon Houng
• Format: Others
• Language: en_US
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/82291668268879606551

碩士 === 國立成功大學 === 微電子工程研究所碩博士班 === 95 === A three-dimensional model with finite-difference and time-domain (FDTD) method was established to investigate the enhancement of the light output intensity in improved light-emitting diodes (LEDs) structure. There are two major structures considered in this thesis. One is the AlGaInP LEDs with porous anodic alumina (PAA) film deposited on top surface, and the other is GaN LEDs with bottom pillar (BP) patterned substrate. Through comparing the calculated normalized light extraction intensity from conventional LEDs, AlGaInP LEDs with PAA film and GaN LEDs with BP structure in different dimensions were studied respectively. From the theoretical result, it shows that the light output intensity in the AlGaInP LEDs with PAA film involved could be enhanced by about 35%. On the other hand, an improvement of the GaN LED with BP patterned substrate could be obtained by about 30%. The influence of these two structures on the light output intensity of LEDs could be explained by the physic model of light interaction. In addition, the practical fabrications of porous anodic alumina film and bottom pillar were both carried out. The experimental results of PAA and BP structures also show the same trend to the theoretical calculations.