Full-Spectral Fine-Tuning Visible Emissions from Cation Hybrid Cs1-mFAmPbX3 (X = CI, Br, and I, 0 ≤ m ≤ 1) Quantum Dots

Full-color visible emissions are particularly crucial for applications in displays and lightings. In this work, we developed a facile room-temperature ligand-assisted supersaturated recrystallization synthesis of monodisperse, cubic structure Cs(1-m)FA(m)PbX(3) (X = Cl, Br, and I or their mixtures Cl/Br and Br/I, 0 <= m <= 1) hybrid perovskite quantum dots (QDs). Impressively, cation substitution of Cs+ by FA(+) was beneficial in finely tuning the band gap and in exciton recombination kinetics, improving the structural stability, and raising the absolute quantum yields up to 85%. With further assistance of anion replacement, full-spectral visible emissions in the wavelength range of 450-750 nm; narrow full width at half-maxima, and a wide color gamut, encompassing 130% of National Television System Committee television color standard, were achieved. Finally, Cs(1-m)FA(m)PbX(3-)polymer films retaining multicolor luminescence are prepared and a prototype white light-emitting diode device was constructed using green Cs(0.1)FA(0.9)PbBr(3) and red Cs(0.1)FA(0.9)Br(1.5)I(1.5) QDs as color converters, certainly suggesting their potential applications in the optoelectronics field.