Modeling and Monte Carlo simulation of photon transmission in glass-packaged WLEDs

Luminous efficiency is a key factor affecting the luminous performance of white light-emitting diodes (WLEDs). However, the mechanism and photon transport process in WLEDs encapsulated with multilayer films have not been elucidated. In this work, the effect of five different encapsulated inorganic glasses on the luminescence efficiency of WLEDs was investigated by using the Monte Carlo method. Compared with the conformal coating method, the away-from-coating method is more beneficial to improve the light output of WLEDs. The results show that the optical property of WLEDs is closely related to the concentration of phosphor and the thickness of the fluorescent glass. In addition, compared with other fluorescent glasses, fluorophosphate fluorescent glass has higher blue and yellow light transmittance and lower yellow light loss rate, which is suitable to be used as packaging materials to effectively improve the light output efficiency of WLEDs.