Phosphorus Halides for Highly Luminescent InP Quantum Dots

We propose a time resolved and contrast matched SANS experiment to establish the effect of PX3 (where X = Cl, Br, I) treatment on ligand-capped indium phosphide quantum dots (InP QDs) and to characterise the resulting shelled dodecanthiol-capped InP@ZnS QDs. PX3 treatment leads to an enormous enhancement in the quantum yield of these materials (5% to >70%). Previously, in RB2420416, we identified the role of PCl3 in the treatment process. We have now extended our treatment approach across the phosphorus halide family and observed a greater increase in quantum yield performance, but a differing shift in the absorption/emission profile of the InP QDs. We therefore wish to explore these new treatments and compare their effects with that of PCl3. Contrast-matching SANS measurements are crucial here to separately visualise changes in the InP core and the alkyl shell of the capping ligand. In-situ measurements are required, as the treated InP QDs are particularly unstable post-treatment. and prior to shelling. Beamtime on SANS2D is preferred due to the requirement of a wide Q-range in a single shot.