Chemical synthesis and optical, structural, and surface characterization of InP-In(2)O(3) quantum dots

InP-In(2)O(3) colloidal quantum dots (QDs) synthesized by a single-step chemical method without injection of hot precursors (one-pot) were investigated. Specifically, the effect of the tris(trimethylsilyl)phosphine, P(TMS)(3), precursor concentration on the QDs properties was studied to effectively control the size and shape of the samples with a minimum size dispersion. The effect of the P(TMS)(3) precursor concentration on the optical, structural, chemical surface, and electronic properties of InP-In(2)O(3) QDs is discussed. The absorption spectra of InP-In(2)O(3) colloids, obtained by both UV–Vis spectrophotometry and photoacoustic spectroscopy, showed a red-shift in the high-energy regime as the concentration of the P(TMS)(3) increased. In addition, these results were used to determine the band-gap energy of the InP-In(2)O(3) nanoparticles, which changed between 2.0 and 2.9 eV. This was confirmed by Photoluminescence spectroscopy, where a broad-band emission displayed from 2.0 to 2.9 eV is associated with the excitonic transition of the InP and In(2)O(3) QDs. In(2)O(3) and InP QDs with diameters ranging approximately from 8 to 10 nm and 6 to 9 nm were respectively found by HR-TEM. The formation of the InP and In(2)O(3) phases was confirmed by X-ray Photoelectron Spectroscopy.