title: Patterned structure of remote phosphor for phosphor-converted white LEDs.
abstract: High efficiency white light-emitting diodes with superior color-mixing have been investigated. It is suggested that the patterned remote phosphor structure could improve the uniformity of angular-dependent correlated color temperature (CCT) and achieve high chromatic stability in wider operating current range, as compared to the conventional remote phosphor coating structure. In this experiment, we employed a pulse spray coating method to place the patterned phosphor on the package and to leave a window region. The window area, a clear space without coating of the phosphor not only increases the extraction efficiency of blue rays at large angle, but also improves the stability of angular-dependent CCT. Moreover, the CCT deviation could be reduced from 1320 K to 266 K by this patterned remote phosphor method, and the stray blue/yellow light within the package can be effectively reduced and controlled. The design was verified both experimentally and theoretically.
authors: Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan, China. hckuo@faculty.nctu.edu.tw
authors: Hao-Chung
authors: HC
authors: Kuo
authors: Cheng-Wei
authors: CW
authors: Hung
authors: Hsin-Chu
authors: HC
authors: Chen
authors: Kuo-Ju
authors: KJ
authors: Chen
authors: Chao-Hsun
authors: CH
authors: Wang
authors: Chin-Wei
authors: CW
authors: Sher
authors: Chia-Chi
authors: CC
authors: Yeh
authors: Chien-Chung
authors: CC
authors: Lin
authors: Cheng-Huan
authors: CH
authors: Chen
authors: Yuh-Jen
authors: YJ
authors: Cheng