Toward high-power-density laser-driven lighting: enhancing heat dissipation in phosphor-in-glass film by introducing h-BN

Abstract

In this work, hexagonal boron nitride (h-BN) nanocrystals as functional additives in a phosphor-in-glass film are shown to substantially increase the luminous performance driven by a blue laser. Microstructural and spectroscopic studies reveal that h-BN particles distributed over the whole glass matrix build in situ a local heat conductive path which effectively accelerates heat dissipation and so greatly relieves the “thermal run-away effect”. The developed composite material with fine thermal manipulation may be a promising phosphor color converter for high-power-density laser-driven lighting.

Realizing High‐Power Laser Lighting: Artfully Importing Micrometer BN into Ce: GdYAG Phosphor‐in‐Glass Film

“…The micrometer BN has a higher TC and forms a strong heat transfer network, thus reducing the temperature of PiG films under laser irradiation to improve the optical performances. [ 53,54 ] As shown in Figure 6e, the ST of the sample is substantially increased from 3.12 to 5.42 W mm −2 , and the LF is also raised from 260.6 to 354.1 lm after adding 12 wt% micrometer BN. More importantly, it can be seen from Figure 6f that the sample can be applied to a variety of laser lighting devices (see Table S6 for sample size information of each device package), demonstrating great application prospects in the field of solid state lighting.…”

YAG:Ce PiGF@Alumina‐Substrate in a Reflection Mode for High‐Brightness Laser‐Driven Projection Display

“…Recently, incorporating hexagonal boron nitride (h-BN) with a high thermal conductivity of ≈30 W m −1 K −1 in PiGFs has been proved to act as an optical medium to enhance light scattering, a heat sink to reduce the temperature, and a protective layer to prevent phosphors from oxidation. [47][48][49] However, the reported BN-added PiGFs still required the supporting substrate such as alumina or sapphire plate. We believe that cosintering YAG:Ce phosphors with h-BN slurry to produce novel YAG:Ce composite film using h-BN as thermoformable all-ceramic matrix [50] is an effective and feasible route to avoid the usage of alumina substrate.…”

High color rendering and high-luminance laser lighting using all inorganic nitride phosphor films

“…Therefore, the flexible design of PiG-Fs can not only guarantee a high blue light absorption efficiency, but also a high saturation threshold, thus a tight bonding of film and substrate can be achieved. 30,31 For example, YAG:Ce PiG bears a maximum laser power density of only ∼3.5 W mm −2 , much lower than the value reported in PiG-F. 32 The LSN:Ce (La 3 Si 6 N 11 :Ce 3+ )-PiG shows a saturation threshold of just 5.5 W mm −2 , 33 while the LSN:Ce PiG-F is capable of withstanding a laser power density as high as ∼12.9 W mm −2 . 34 Both demonstrated the enormous potential of PiG-Fs in high brightness pc-wLD.…”