A Double Zn and Ga\nModification Strategy for Highly\nEfficient Deep Blue InP/ZnSeS/ZnS Quantum Dots

InP quantum dots (QDs) are regarded as the most promising\nstar\nmaterial to replace Cd-based QDs due to their excellent properties\nof low toxicity and tunable luminescence in the visible to infrared\nrange. Red and green InP QDs have been shown to have excellent performance\ncomparable to that of Cd-based QDs, but in contrast, blue InP QDs\nare still lagging behind. The smaller size of the core is a challenge\nfor synthesizing high-performance blue InP QDs compared with red and\ngreen QDs. In this study, deep blue-emitting InP QDs were synthesized\nusing a cheaper and safer phosphorus source: tris(dimethylamino)phosphine\n((DMA)<sub>3</sub>P). A double Zn and Ga modification was applied\nto modulate the emission of InP QDs. A strategy for synthesizing deep\nblue luminescent In(ZnGa)P QDs was proposed, and Zn(Ac)<sub>2</sub> was used as a precursor to react with (DMA)<sub>3</sub>P to synthesize\nblue InP QDs. Doping elemental Zn during nucleation inhibited the\ngrowth of the InP crystals and narrowed the lattice. Then, the Ga\nelement further increases the material band gap by cation exchange.\nBy introducing GaI<sub>3</sub> into the synthesis process and utilizing\nthe cation-exchange mechanism, deep blue emission InP QDs was realized.\nTunable deep blue emission of InP QDs changed from 478 to 447 nm was\nachieved by this strategy. Specially, an 84% photoluminescent quantum\nyield is obtained for 457 nm emission QDs. This study provides clues\nfor InP QDs to be emitted in the deep blue region, with the aim of\nconstructing efficient deep blue QDs light-emitting diodes.