This study explores the realization of high-efficiency white LED lighting by applying cyan-emitting quantum dot (CQD) and red-emitting quantum dot (R-QD) deposition without any host matrix onto a yellow-emitting phosphor-in-glass (YPIG) substrate using an aerosol-assisted deposition (AAD) process. The AAD process facilitates the direct formation of densely packed QD-deposited layers on the substrate, effectively addressing challenges such as optical efficiency loss and degradation typically associated with organic host matrices. C-QD and R-QD coatings, deposited with thicknesses of 0.84 μm and 0.77 μm on the upper and lower Y-PIG substrate, exhibited robust color conversion properties. These films achieved a luminous efficacy of 77 lm/W and a high color rendering index (CRI) of 96.8 under blue light excitation. The dual-layer structure produced highquality light closely resembling natural daylight, as confirmed through real image. Consequently, the research suggests the potential of AAD-based QD deposition to achieve superior performance without relying on host matrices, offering a viable solution for high-efficiency lighting applications. Further optimization of deposition parameters and exploration of diverse substrates and QD material combinations are expected to expand the applicability of this technique in future research.

Recently, remote phosphor is reported for white LED enhancing of phosphor efficiency compared with conventional phosphor-based W-LED. In this study, Remote phosphor was produced by screen printing coating on glass substrate with phosphor contents rated paste and heat treatment. The paste consists of phosphor, lowest softening glass frit and organic binders. Remote phosphor can be well controlled by varying the phosphor content rated paste. After mounting remote phosphor on top of blue LED chip, CCT, CRI, and luminance efficiency were measured. The measurement results showed that CCT, CRI. and luminance efficiency were 6,645, 68, and 1,161 n/W in phosphor 80 wt.% remote phosphor sintered at 600℃.

We developed a package of remote phosphor structure having blue LED chips and phosphors physically separated, and the characteristics were evaluated according to different classifications of phosphor coatings. Remote phosphor was produced by screen printing coating on glass substrate with phosphor content rated paste and heat treatment. After mounting Remote phosphor, which has been classified according to number of coatings, on top of blue LED chips, luminous flux, luminous efficacy, CCT and CRI were measured. The measurement results showed the most suitable characteristics of white LED package as a general light source when the content rate of phosphor in Remote phosphor was 80 wt.% with 3 layers of coatings and thickness over 12 μm.

Citations

• Optical Properties as Process Condition of Color Conversion Lens Using Low-softening Point Glass for White LED
  Yoo-Jin Chae, Mi-Jai Lee, Jong-Hee Hwang, Tae-Young Lim, Jin-Ho Kim, Hee-Suk Jeong, Young-Sik Lee, Deug-Joong Kim
  Journal of the Korean Ceramic Society.2013; 50(6): 454.     CrossRef