SYNTHESIS AND CHARACTERIZATION OF INP QUANTUM DOTS

Colloidal dispersions of quantum dots (QDs) of crystalline InP were synthesized starting from a chloroindium oxalate complex and P(SiMe(3))(3). An InP precursor was formed from the reactants at room temperature; heating the precursor in a solution of trioctylphosphine oxide at 270 degrees C for several days produced InP QDs with a mean diameter of 26.1 +/- 7.5 Angstrom (determined by counting lattice fringes in a TEM micrograph). From the known QD size distribution and its absorption spectrum, we used a theoretical model to calculate the dependence of InP QD bandgap on QD size. From these results we could then calculate the size distribution of any InP colloid from its absorption spectrum. It was found that preparing the InP precursor with an excess of In3+ and then heating it in a mixture of trioctylphosphine oxide and trioctylphosphine at 270 degrees C for 3 days produced a very narrow QD size distribution with a mean diameter of 25 +/- 1.9 Angstrom.