Abstract

To further improve the luminous efficiency of LED lightings, this Letter proposes a chip-on-board (COB) device by combining diced staggered V-shaped patterns and remote phosphors. The results show that the V-shaped patterned COB (V-COB) with vertex angles from 120º to 150º can achieve a ∼17% output power increase (OPI) compared to the conventional COB. V-COB remote phosphor devices (RPDs) are then manufactured and tested. The luminous efficiency of the proposed RPD represents an 11.6% increase at the correlated color temperature of ∼3000 K. Such an improvement can be attributed to both the decreases of total internal reflections and phosphor backscatterings.

© 2017 Chinese Laser Press

Patterned structure of REMOTE PHOSPHOR for phosphor-converted white LEDs

Hao-Chung Kuo, Cheng-Wei Hung, Hsin-Chu Chen, Kuo-Ju Chen, Chao-Hsun Wang, Chin-Wei Sher, Chia-Chi Yeh, Chien-Chung Lin, Cheng-Huan Chen, and Yuh-Jen Cheng
Opt. Express 19(S4) A930-A936 (2011)

Simple prismatic patterning approach for nearly room-temperature processed planar remote phosphor layers for enhanced white luminescence efficiency

Oh Hyeon Kwon, Jun Sik Kim, Jin Woo Jang, and Yong Soo Cho
Opt. Mater. Express 8(10) 3230-3237 (2018)

Curved remote phosphor structure for phosphor-converted white LEDs

Shang-Ping Ying, Han-Kuei Fu, and Huang-Zong Tu
Appl. Opt. 53(29) H160-H164 (2014)

Color uniformity enhancement for COB WLEDs using a remote phosphor film with two freeform surfaces

Jiasheng Li, Zongtao Li, Guanwei Liang, Shudong Yu, Yong Tang, and Xinrui Ding
Opt. Express 24(21) 23685-23696 (2016)

Improved CCT uniformity of white LED using remote phosphor with patterned sapphire substrate

Kuan-Chieh Huang, Teng-Hsien Lai, and Cheng-Yen Chen
Appl. Opt. 52(30) 7376-7381 (2013)