Fabrication of a Wide Color Gamut pc-WLED Surpassing 107% NTSC Based on a Robust Luminescent Uranyl Phosphate

The development of green-light-emitting phosphors with combined narrow emission band, high quantum efficiency, and high chemical resistance remains to date one of the most challenging issues for wide color gamut WLED fabrication. In this work, uranyl ion (UO22+) endowed with broad and intense absorption capacity in blue region was incorporated into a rigid phosphate skeleton (namely HUP-2, formulated as (H3O)­UO2PO4·(H2O)3) and results in near-unity internal and external quantum efficiencies (IQE/EQE) of up to 93.66 and 82.05% under the excitation of 282 nm, respectively. Benefiting from the structural robustness, the emission of HUP-2 displays excellent resistance to humidity, UV to visible light irradiation, and elevated temperature. The distinct electronic structure of UO22+ coupled with vibration gives rise to narrow emission bands (full width at half-maximum peak, FWHM = 43 nm), thus leading to a wide color gamut reaching 107.6% of the National Television System Committee standard (NTSC) of the fabricated pc-WLED. This work sheds light on the great potential of UO22+-containing phosphor for the application in liquid crystal display (LCD) backlighting.