Indium phosphide (InP) nanocrystals have emerged as a viable alternative to heavy metal-based colloidal quantum dots for optoelectronic applications. Traditionally, the presence of trace amounts of water during the synthesis of colloidal quantum dots is considered an undesired impurity because it prevents or slows down colloidal growth and alters the surface properties. Here, we report that fine-tuning the amount of trace water is the key for achieving size-focused growth of monodisperse InP nanocrystals synthesized using aminophosphine precursors. Using solid-state and solution nuclear magnetic resonance, we investigated the role of trace amounts of water in surface oxidation and precursor conversion reactions. Molecular insights from UV-vis spectroscopy and NMR revealed a profound contrast between the growth rates of the nanocrystals upon the addition of water to the reaction system. We demonstrate that by addition of a specific amount of water, the reactivity of the phosphorous precursor can be tuned to enable a constant supply of monomer throughout the reaction. Under an optimal precursor conversion rate, a size-focused growth behavior that is rare for InP nanocrystals is observed, suggesting the presence of an artificial LaMer-like growth regime.
|Original language||English (US)|
|Number of pages||8|
|Journal||Chemistry of Materials|
|State||Published - Apr 28 2020|
ASJC Scopus subject areas
- Chemical Engineering(all)
- Materials Chemistry