Fig. 1 Development of WLED (a) InGaN蓝光芯片/YAG:Ce黄色荧光粉白光LED; (b) RGB混合荧光粉白光LED; (c)单基质白光LED[4] (a) blue light emitting InGaN chips/YAG:Ce yellow light emitting phosphor WLED; (b) WLED based on red-green-blue (RGB) emitting color phosphors; (c) WLED based on single-phase phosphor[4,5,6]

Fig. 2 PL spectra of CaSrSiO4:Eu2+ phosphors sintered at different temperatures (a) and fabricated with different Eu2+ concentrations (b)[22]

Fig. 3 EL spectra (a) of the white LED fabricated by using phosphors and 400 nm GaN-based LED chips, CIE (x, y) chromaticity diagram (b) with insets showing digital images of the fabricated white LED[22]

Fig. 4 (a) PLE and PL spectra of as-synthesized Ba3Y1.3Eu0.7B6O15 phosphors (λem=?593?nm and λex=?393?nm) at room temperature, (b) PL spectra of Ba3Y2-xEuxB6O15 (x?=?0.1, 0.3, 0.5, 0.6, 0.7, 0.9 and 1.0) phosphors with the inset illustrating the variation of the PL intensity (593?nm) on the concentration of Eu3+[23]

Fig. 5 Emission spectra (a) and CIE chromaticity diagram (b) of CYAO phosphors with different Dy3+ doping concentrations[24]

Fig. 6 Energy transfer diagram of CaYAl3O7 phosphors[24]

Fig. 7 Emission and excitation spectra of CNPO:0.01Eu2+ phosphor[33]

Fig. 8 PL spectra of the CNPO:0.01Eu2+, nMn2+(n = 0, 0.1, 0.2, and 0.4) under the excitations at 276 (a), 320 (b), and 355 nm (c), respectively; The photos of the phosphors (d) excited by 365 nm UV lamp (bottom row), and photos obtained in daylight environment (upper row). The photos 1-4 correspond to n=0, 0.1, 0.2, and 0.4, respectively[33]

Fig. 9 Electroluminescence spectra of the WLED operated under various currents of 20 to 60 mA. Inset: the variation in CIE chromaticity coordinates of the WLED under various currents[57]

Fig. 10 Schematic crystal structure of AVO3[58]

Fig. 11 Controllable photoluminescence (a) Optical images of solution and film samples with different bandgaps under a 365 nm UV lamp; (b) Optical absorption; (c) Photoluminescence spectra of IPQDs with different composition[65]