Far-field of GaN film-transferred green light-emitting diodes with two-dimensional photonic crystals.
Far-field distributions of GaN-based photonic crystal (PhC) film-transferred light-emitting diodes (FT-LEDs) were investigated. The thickness of the device is about 840 nm. The emission wavelength is around 520 nm. The PhC region is a square lattice with a/lambda around 0.5. Angular-resolved measurements in the Gamma-X and Gamma-M directions were made in the polarized-resolved manner. Guided mode extraction behavior in agreement with the two-dimensional free-photon band calculation was observed. In addition, the pseudo-TM behavior for the non-collinearly coupled modes was observed. The azimuthal-mapping of the angular-resolved spectra revealed the evolution of the collinearly and the non-collinearly coupled modes. Furthermore, the light enhancement of approximately 2.7x and the collimation angle about 102.3 degrees were achieved.
Lai
Chun-Feng
CF
Department of Photonics and Institute of Electro-Optical Engineering, National Chiao-Tung University, Hsinchu 300, Taiwan, ROC.
Chi
Jim-Yong
JY
Kuo
Hao-Chung
HC
Yen
Hsi-Hsuan
HH
Lee
Chia-En
CE
Chao
Chia-Hsin
CH
Hsueh
Han-Tsung
HT
Yeh
Wen-Yung
WY
D003116:Color; D003460:Crystallization / Q000379:methods; D005708:Gallium / Q000737:chemistry*; D008029:Lighting / Q000295:instrumentation*; D008422:Materials Testing; D008567:Membranes, Artificial; D017785:Photons; D012666:Semiconductors
D008567:Membranes, Artificial; C473348:gallium nitride; D005708:Gallium