The construction of stable and efficient materials that emit blue and green light remains a challenge. Among the blue light materials reported, metal-organic framework (MOF) materials are rarely reported as blue phosphors due to their weak luminescence intensity. Based on the construction of CsPbBr₃@MOF (CPB@MOF), an innovative idea was proposed to simultaneously enhance the green luminescence of CPB and the blue luminescence of MOF through the interaction between CPB and MOF for the first time. As expected, the blue luminescence from CPB:7%SCN⁻@0.5%MOF:Eu as well as the green luminescence from 5%CPB:7%SCN⁻@MOF:Eu was sufficient to construct high-performance light-emitting diode (LED) devices and further excite solar cells to generate stable photoelectric signals. The white LED (WLED) device with excellent color quality (color rendering index (CRI) = 96.2) and correlated color temperature (CCT = 9688 K) can be constructed by using the obtained blue-emitting CPB:7%SCN^-@0.5%MOF:Eu, green-emitting 5%CPB:7%SCN⁻@MOF:Eu, and red-emitting PPB:30%Mn²⁺. The density functional theory (DFT) theoretical calculation results indicate that the p orbital of Pb plays the major role in the conduction band, and the p orbital of Br plays the major role in the valance band of CPB and CPB:SCN⁻. While the p orbital of O plays the major role in both the conduction band and valance band of MOF. The heat capacity of CPB and CPB:SCN⁻ separately reaches the Dulong–Petit limit at 200 and 400 K, indicating that the thermal stability of CsPbBr₃ increases after SCN⁻ doping.

The preparation of high-efficiency phosphor is the key to the construction of white light-emitting diode (WLED) devices and their application in indoor photovoltaics. Compared with YVO₄, InVO₄ is not suitable as the host material of lanthanide ions because of its strong self-luminescence. Here, the work focused on combining the broadband emission from InVO₄ and the red luminescence from YVO₄:Eu³⁺ to obtain enhanced and stable multicolor luminescence. The band structure, density of state, and optical properties were studied by density functional theory. The spectral configuration of YVO₄:In³⁺/Eu³⁺ with (112) surface appears to be broadening and redshifts with increasing layer number. When the In³⁺ concentration is 3.5 mol%, the YVO₄:30%Eu³⁺/In³⁺ emits the strongest light. The Judd-Ofelt parameter Ω₂ of YVO₄:In³⁺/Eu³⁺ increases with increaing In³⁺ concentration, indicating that the symmetry decreases. By adjusting In³⁺/Eu³⁺ contents, the YVO₄:In³⁺/Eu³⁺ not only can emit white light with a color rendering index of 95, but also can be used as high-efficiency red phosphor to build WLED devices with blue emitting N/Tb codoped carbon quantum dots (CQDs-N:Tb³⁺) and green emitting MOF:Tb³⁺ (MOF = metal organic framework), for which the color rendering index can also reach 95 and the color temperature is 5549 K. The manufactured WLED devices were further used to excite the silicon solar cell and make it show good photoelectric characteristics.

High-quality single-component white phosphors are instrumental in realizing high-efficiency devices. Rare earth fluorides and carbon quantum dots have great potential in the white light-emitting diode (WLED) field due to their unique advantages. Here, Rare-earth single atom based NaGdF₄:Tb³⁺/Eu³⁺@C:N/Eu³⁺ single phosphor with tunable full-color luminescence was reported. The results of density functional theory (DFT) calculation and experimental characterization show that C atoms cannot be replaced by Eu³⁺, but C atoms are more favorable for anchoring Eu³⁺ single atoms. The DFT was employed to optimize the structures of the C:N/Eu³⁺ and NaGdF₄:Tb³⁺/Eu³⁺, and calculate the work function, optical properties, and charge density difference. The obtained tunable full-color single phosphor can emit stable light from blue to red or even white. The constructed WLED devices also have stable and excellent color performance, that is, a color rendering index of up to 95 and a lower color temperature, and it has broad application possibilities in WLEDs.

A novel host-guest luminous system with enhanced near-UV light absorption thereby enhanced luminescence are designed based on the synergism of quantum confinement, spatial confinement, and antenna effect, where ultrasmall Y₂O₃:Eu³⁺ nanocrystals are fixed inside MOF (Eu/Y-BTC) as supporting structure. The Eu/Y-BTC not only limits the size and leads to lattice distortion of Y₂O₃:Eu³⁺ nanocrystals and controls the distance between nanocrystals, but also promotes the light absorption and emission. The significantly red-shifted and broadened charge transfer band of Y₂O₃:Eu³⁺/(Eu/Y-BTC) leads to the excellent applications of Y₂O₃:Eu³⁺ in white light-emitting diodes (LEDs). Our results show that white light with superior color quality (CRI>90) and extremely high luminous efficacy (an LER of 335 lm/W) could be achieved using Y₂O₃:Eu³⁺/(Eu/Y-BTC) as red phosphor. The Y₂O₃:Eu³⁺/ (Eu/Y-BTC) also improves the photoelectric performance of dye-sensitized solar cells (DSSCs), not only because Y₂O₃:Eu³⁺/(Eu/Y-BTC) has a large specific surface area and the adsorption amount of the dye is increased, but also because the valence band position of Y₂O₃:Eu³⁺/(Eu/Y-BTC) is 2.41 eV, which can provide an additional energy level between the TiO₂ and dye, promoting electron transfer. For these advantageous features, the multifunctional Y₂O₃:Eu³⁺/(Eu/Y-BTC) composite product will open new avenues in white LEDs and DSSCs.