An effective emission model of phosphor film is proposed by using bidirectional scattering distribution function system (BSDF), and the model is verified by white light-emitting diodes (LEDs) with conformal and remote phosphor structure. The emission model is built to clarify the optical characteristics by analyzing the angular-dependent distribution of emission and excitation behaviors in phosphor film. The white LEDs with conformal and remote phosphor structure are also fabricated for experimental comparison. The uniformity of angular correlated color temperature (CCT) in white LEDs can be determined by the angular distribution of blue and yellow light, which is in turns decided by the refractive index variation between chip a©nd phosphor layers. Finally, the experimental results are found to have good agreement with the simulation results performing by the Monte Carlo method.
© 2013 IEEE
Kuo-Ju Chen, Hsin-Chu Chen, Chien-Chung Lin, Chao-Hsun Wang, Chia-Chi Yeh, Hsin-Han Tsai, Shih-Hsuan Chien, Min-Hsiung Shih, and Hao-Chung Kuo, "An Investigation of the Optical Analysis in White Light-Emitting Diodes With Conformal and Remote Phosphor Structure," J. Display Technol. 9, 915-920 (2013)