Effects of TiO2 in graphene-quantum-dot film on lighting color uniformity of a white light-emitting diodes

Abstract

Improvement in color uniformity of white light-emitting diodes (WLED) is one of the imperative goals for high-quality solid-state illumination. The conventional WLED model with a single yellow phosphor YAG:Ce³⁺ (TiO₂@GD) is proposed to fulfill this goal. The TiO₂@GD composites prove to possess excellent biocompatibility, low toxicity, and thermal and chemical stability, holding great potential in high-power WLED production. By maintaining a constant GDs content of 10 wt%, the research explores the impact of varying TiO₂ doping concentrations on the lighting performance of the WLEDs via the mean of light scattering. The TiO₂@GD layer also induces a red-shift in the emitted light spectrum, contributing to a reduction in color variation. While a decline in luminosity and color rendering performance becomes evident with excessive TiO₂ content, the study underscores the potential of TiO₂@GD as a viable diffusing layer for LEDs to obtain improved angular uniformity of color distribution.