Design of a Novel La3Si6N11:Ce3+ Phosphor-in-Glass Film for High Power Laser Lighting: Luminous Efficiency toward 200 lmW–1

Abstract

Inorganic fluorescent glass films have been widely considered in the field of high power laser lighting because of their excellent comprehensive properties as fluorescent conversion materials. Herein, we adjust the optimum sintering temperature to prepare a series of La3Si6N11:Ce3+ phosphor-in-glass films (LSN PiFs) with excellent optical properties on a single sapphire structure. The prepared LSN PiF has ultrahigh internal quantum efficiency (IQE) (98%) and excellent thermal stability. The thermal conductivity at room temperature can reach 9.8 Wm–1 K–1. When the temperature is 100 °C, the fluorescence intensity can still be maintained. The LSN:Ce phosphor particles did not react with the glass matrix and retained the original luminescence properties. Moreover, by further adjusting the concentration and thickness of LSN PiF, the luminous flux and luminous efficiency of LSN PiF under optimal conditions can reach 1071.73 and 207.58 lmW–1 under the excitation of 460 nm, which is the optimal result reported so far. In addition, the color rendering index (CRI) and low color temperature (CCT) are 64.05 and 5612.6 K, respectively, and the color coordinates are all close to the white light region. All the results show that LSN PiF has great application prospects in the high quality and high brightness laser lighting field.