Directional light extraction enhancement from GaN-based film-transferred photonic crystal light-emitting diodes

作者：Lai Chun Feng^*; Chao Chia Hsin; Kuo Hao Chung; Yen His Hsuan; Lee Chia En; Yeh Wen Yung

来源：Applied Physics Letters, 2009, 94(12): 123106.

DOI：10.1063/1.3106109

• gallium compounds
• III-V semiconductors
• light emitting diodes
• photonic crystals
• wide band gap semiconductors

Experimental investigation of the directionality in the far-field pattern and light extraction enhancement in collected cone were performed in GaN-based film-transferred photonic crystal (PhC) light-emitting diodes (FTLEDs). Angular-resolved measurement revealed directional profile and azimuthal anisotropy in the far-field distribution with guided modes extraction. Good agreement according to Bragg's diffraction theory and free photon band structure were achieved. The light enhancement in PhC FTLEDs compared to non-PhC FTLEDs within the collection cone angle was obtained according to measured three-dimensional far-field patterns. In a /- 20 degrees collection cone, collected light was enhanced by a factor of similar to 2.4 for the collimated PhC FTLED.

• 出版日期2009-3-23