Light extraction efficiency enhancement of flip-chip blue light-emitting diodes by anodic aluminum oxide.

Yi-Ru Huang,Chun-Ping Jen,Yao-Ching Chiu,Chih-Ming Lai,Shao-Ying Ting,Po-Jui Chiang,Kuan-Chieh Huang,Hsiang-Chen Wang,Snow H Tseng

doi:10.3762/bjnano.9.152

Abstract

We produced an anodic aluminum oxide (AAO) structure with periodic nanopores on the surface of flip-chip blue light-emitting diodes (FC-BLEDs). The nanopores had diameters ranging from 73 to 85 nm and were separated by distances ranging from approximately 10 to 15 nm. The light extraction efficiency enhancement of the FC-BLEDs subjected to different durations of the second pore-widening process was approximately 1.6–2.9%. The efficiency enhancement may be attributed to the following mechanism: periodic nanopores on the surface of FC-BLEDs reduce the critical angle of total reflection and effective energy transfer from a light emitter into a surface plasmon mode produced by AAO.

Highlights

Light-emitting diodes (LEDs) are widely used in various fields, such as optical communication and automobile lighting [1,2,3,4,5,6]
The scanning electron microscopy (SEM) images of samples AAO60, AAO70, and AAO80 are shown in Figure 1a, Figure 1b, and Figure 1c, respectively
The SEM results indicate that the pores gradually enlarge and that the distance between pores shortens as the duration of the second porewidening process is extended

Summary

Introduction

Light-emitting diodes (LEDs) are widely used in various fields, such as optical communication and automobile lighting [1,2,3,4,5,6]. AAO is used to produce a periodic nanostructures on high-luminance flip-chip blue LEDs (FC-BLEDs) to enhance the LEE [26,27].

Results

Conclusion