Pseudohalogen Ammonium Salt-Assisted Syntheses of Large-Sized Indium Phosphide Quantum Dots with Near-Infrared Photoluminescence

Abstract

The development of indium phosphide (InP)-based quantum dots (QDs) with a near-infrared (NIR) emission area still lags behind the visible wavelength region and remains problematic. This study describes a one-step <i>in situ</i> pseudohalogen ammonium salt-assisted approach to generate NIR-emitted InP-based QDs with high photoluminescence quantum yields (PLQYs). The coexistence of NH₄⁺ and PF₆^- ions from NH₄PF₆ may <i>in situ</i> synchronously etch and passivate the surface oxides and impede the creation of traps under the whole growth process of InP QDs. Experimental findings demonstrated that the <i>in situ</i> pseudohalogen ammonium salt-assisted syntheses technique may feature emission at a full width at half-maximum (fwhm) peak as fine as ∼45 nm and broaden the emission range to around ∼780 nm. A two-step approach for ZnS shells was developed to further improve the PLQY of NIR-emitted InP QDs. Furthermore, the constructed high-power intrinsically stretchable NIR color-conversion film employing the InP-based QDs/polymer composites presented excellent luminescence conversion ability and stretchability.