High luminous efficacy and enhanced stability of QDs via a network silica and methylphenyl silicone hybrid for the long-term operation of on-chip white light-emitting diodes with a wide color gamut

•We present a facile synthesis method for preparing network (NW)-silica-coated green- and red-emitting Cd-based quantum dots [pristine GRQDs].•The main novelty of this method involves the coating of oil-soluble QDs with a silica shell without performing a ligand exchange or phase transfer.•The as-synthesized NW–silica-coated G(R)QD nanoparticles [G(R)QD@NW–silica NPs] presented evident enhancements against the high-energy blue-light radiation, a water medium, and heat.•This study proposes an effective approach for improving the luminous efficiency and long-term operation of composite QD-WLEDs, which have tremendous potential for use in next-generation display applications such as full-color mini-LEDs and micro-LEDs. We present a facile synthesis for preparing network (NW)–silica-coated green- and red-emitting Cd-based quantum dot [pristine GRQD] powders. Mixing these powders with a methylphenyl silicone (MPS) encapsulant leads to an excellent long-term operation as QD-on-chip white light-emitting diodes (WLEDs). Pristine QDs coated with NW– or chain (Ch)–silica structures (determined by the synthesis temperature) were obtained by a hydrolysis/condensation pathway. Experimentally, in a harsh stability analysis, the as-synthesized NW–silica-coated G(R)QD nanoparticles [G(R)QD@NW–silica NPs] presented evident enhancements against the high blue energy irradiation (~45 mW), a water medium (aging for 1,000 hr), and heat (to 300°C) when compared with that of pristine G(R)QDs. Notably, the GRQD@NW–silica/MPS hybrid WLEDs (composite QD–WLEDs) were subjected to a high temperature and high humidity condition (85°C/85% RH) for long-term aging, which demonstrated that the luminous flux was maintained at 100% after aging for 1,000 hr (that of pristine QD–WLEDs decays 23%). Additionally, composite QD–WLEDs were also subjected to a long-term reliability analysis (25°C/60% RH) and exhibited an outstanding reliability with only 17% decay after continuous operation for 2,352 hr, as well as a high luminous efficacy of 81 lm/W and a wide color gamut (122% of NTSC). This study proposes an effective approach for improving the luminous efficiency and long-term operation of composite QD–WLEDs, which have tremendous potential for use in next-generation display applications such as full-color mini-LEDs and micro-LEDs. We present a facile synthesis method for preparing network-silica-coated full-color Cd-based quantum dots, which demonstrated excellent stability for encapsulated into