All-Inorganic Light Convertor Based on Phosphor-in-Glass Engineering for Next-Generation Modular High-Brightness White LEDs/LDs

Superhigh brightness, reliability, and modularization are three key features of state-of-the-art high-brightness solid state lighting, such as high-power white light-emitting diodes (white LEDs) and white laser diodes (white LDs). However, these features are inevitably limited by the organic resin packing material, as a crucial component of the white lighting device, because of its unstable property at high temperature and low thermal conductivity. Here, we report a robust light convertor that can simultaneously play key roles as a phosphor and an alternative encapsulating material via phosphor-in-glass (PiG) engineering. We employed a combination of powder X-ray diffraction, scanning electron microscope, energy dispersive spectrometer (EDS), EDS mapping, confocal laser scanning microscope, cathodoluminescence mapping, in conjunction with micro-PL system with a point-by-point scanning mode to study the detailed structure of PiG samples. This Y3Al5O12:Ce3+-based PiG exhibits a high external quantum efficiency of ∼60%, a high thermal conductivity of ∼0.59 W/mK, exceptional thermal stability, and excellent moisture resistance. By combining the as-synthesized PiG with high-power blue chip-on-board, a high luminous efficacy (92 lm/W) modular white LEDs with a luminous flux up to 1076 lm and a high color rendering modular warm white LEDs (Ra = 90.3 and CCT = 3585 K) are achieved. Moreover, a modular white LDs with a higher luminous efficacy (110 lm/W) is also achieved through blue LDs pumping. The results demonstrate that this easy-fabrication, low-cost, and long-term reliable high-brightness modular white LEDs or white LDs is expected to be a promising candidate for next-generation illumination.