Chlorophyll-inspired in-situ growth of Ti₃C₂-assisted CsPbBr₃ quantum dots for highly stable green-to-deep-blue flexible display devices

With the development of high-resolution display technologies with vision health consideration, the absent emission wavelengths on the long-wavelength blue light (460 nm to 480 nm) of CsPbBr₃ quantum dots (QDs) has become a crucial hindrance for the wide color gamut displays, and the tunable emission wavelengths via size control can unfortunately suffer from the ligand shedding. In the light of chlorophylls, the CsPbBr₃ QD decorated Ti₃C₂ nanosheets (CQDTs) are in-situ synthesized with a controllable emission wavelength range from 455 nm to 505 nm at room temperature. The growth rate of CsPbBr₃ QDs can be retarded due to a relatively lower total energy during the adsorption of precursors on Ti₃C₂ nanosheets, thus the improved monodispersity of resulting QDs in turn results in the photoluminescence quantum yield at 505 nm (∼100%) and at 455 nm (∼42%). Providing with the strong binding energy between CsPbBr₃ QDs and Ti₃C₂ nanosheets, the decomposition of perovskite can be efficiently hindered, endowing an excellent stability. The enhanced stability of the flexible light-emitting films fabricated with CQDT is witnessed with a remained luminescence intensity of 77% (pristine is 45%) after 40 000 bending cycles, and the CQDT LED possesses the chromatic coordinates of (0.06, 0.61), (0.71, 0.28), (0.12, 0.06) with a ∼107% NTSC color gamut.