title: Far-field of GaN film-transferred green light-emitting diodes with two-dimensional photonic crystals.
abstract: 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.
authors.affiliation: Department of Photonics and Institute of Electro-Optical Engineering, National Chiao-Tung University, Hsinchu 300, Taiwan, ROC.
authors.forename: Chun-Feng
authors.initials: CF
authors.lastname: Lai
authors.forename: Jim-Yong
authors.initials: JY
authors.lastname: Chi
authors.forename: Hao-Chung
authors.initials: HC
authors.lastname: Kuo
authors.forename: Hsi-Hsuan
authors.initials: HH
authors.lastname: Yen
authors.forename: Chia-En
authors.initials: CE
authors.lastname: Lee
authors.forename: Chia-Hsin
authors.initials: CH
authors.lastname: Chao
authors.forename: Han-Tsung
authors.initials: HT
authors.lastname: Hsueh
authors.forename: Wen-Yung
authors.initials: WY
authors.lastname: Yeh
mesh_terms: D003116:Color; D003460:Crystallization / Q000379:methods; D005708:Gallium / Q000737:chemistry*; D008029:Lighting / Q000295:instrumentation*; D008422:Materials Testing; D008567:Membranes, Artificial; D017785:Photons; D012666:Semiconductors
chemical_list: D008567:Membranes, Artificial; C473348:gallium nitride; D005708:Gallium