Synthesis, Surface Chemistry, and Fluorescent Properties of InP Quantum Dots

InP quantum dots (QDs) have great potential as emitters for solid-state lighting, lasing, and bioimaging without the inherent toxicity concern of Cd and Pb-based emitters. Indium phosphide’s small bandgap and high covalency make it uniquely capable of color-pure fluorescence that can be tuned throughout the visible and lower IR spectrum. Until recently, InP-based QDs consistently underperformed when compared with CdSe-based counterparts. Recent efforts to understand indium phosphide’s nonclassical growth mechanisms, control the nanocrystal shape, control in situ formation of surface oxides, and grow thick, uniform shells have produced InP-based QDs comparable to their CdSe competitors with >95% quantum yields (QYs) in red, green, and blue emission wavelengths. This review covers the most common synthetic techniques, the most recent theories on InP formation mechanisms, the current understanding of InP surface chemistries, and the breadth of fluorescent properties of InP-based QDs.