Narrow Near-Infrared Emission from InP QDs Synthesized with Indium(I) Halides and Aminophosphine

Abstract

Nonpyrophoric aminophosphines reacted with indium(III) halides in the presence of zinc chloride have emerged as promising phosphorus precursors in the synthesis of colloidal indium phosphide (InP) quantum dots (QDs). Nonetheless, due to the required P/In ratio of 4:1, it remains challenging to prepare large-sized (>5 nm), near-infrared absorbing/emitting InP QDs using this synthetic scheme. Furthermore, the addition of zinc chloride leads to structural disorder and the formation of shallow trap states inducing spectral broadening. To overcome these limitations, we introduce a synthetic approach relying on the use of indium(I) halide, which acts as both the indium source and reducing agent for aminophosphine. The developed zinc-free, single-injection method gives access to tetrahedral InP QDs with an edge length > 10 nm and narrow size distribution. The first excitonic peak is tunable from 450 to 700 nm by changing the indium halide (InI, InBr, InCl). Kinetic studies using phosphorus NMR reveal the coexistence of two reaction pathways, the reduction of transaminated aminophosphine by In(I) and via redox disproportionation. Etching the surface of the obtained InP QDs at room temperature with in situ-generated hydrofluoric acid (HF) leads to strong photoluminescence (PL) emission with a quantum yield approaching 80%. Alternatively, surface passivation of the InP core QDs was achieved by low-temperature (140 °C) ZnS shelling using the monomolecular precursor zinc diethyldithiocarbamate. The obtained InP/ZnS core/shell QDs that emit in a range of 507–728 nm exhibit a small Stokes shift (110–120 meV) and a narrow PL line width (112 meV at 728 nm).

Revealing the Band-Edge Exciton Fine Structure of Single InP Nanocrystals

“…Historically, prototypical CdSe-based core/shell NCs were extensively studied as they offer bright luminescence through the whole visible spectrum but present major environmental and toxicity hazards. Indium phosphide (InP) NCs are a less toxic alternative to Cd-based NCs, − while possessing similar photoluminescence (PL) properties as a result of a suitable bulk band gap. They have thus quickly emerged in a variety of technological applications such as NC-based light-emitting devices, , solar cells, photocatalysts, , and bioimaging …”

Size and Emission Control of Wurtzite InP Nanocrystals Synthesized from Cu3–xP by Cation Exchange

“…Plot of the emission energy as a function of 1/r 2 gives a straight line dependence with the intercept at 1.45 ± 0.02 eV, close to the bulk band-gap value of w-InP. Note that in comparison to the directly synthesized large cubic-phase InP NCs manifesting band-gap PL as red as 740 nm (for a size of 10.5 nm), 16 we could achieve a further red-shifted PL (810 nm for the 10.7 arrested at any time for obtaining the desired NC size (see the Experimental Section). 27 We next studied the reaction mechanism of NOBF 4 by addressing the important role of the DMF solvent and water.…”

Reduced electron relaxation time of perovskite films via g-C3N4 quantum dot doping for high-performance perovskite solar cells

“…29 In addition, less grain boundaries and thickness of perovskite layer are all also key elements contribute to high-efficiency PSCs. 30–34 Large grains can improve the perovskite film morphology and coverage effectively to reach an enhanced light-harvesting under unified light intensity. 35–39…”

“…29 In addition, less grain boundaries and thickness of perovskite layer are all also key elements contribute to high-efficiency PSCs. [30][31][32][33][34] Large grains can improve the perovskite lm morphology and coverage effectively to reach an enhanced light-harvesting under unied light intensity. [35][36][37][38][39] The studies of quantum dots modied PSCs mainly focused on the application of carbon quantum dots (CQDs) in devices, and the application of g-C 3 N 4 QDs in PSCs is rarely reported.…”