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.

本研究提出一项时间分辨衬度匹配小角中子散射（Small Angle Neutron Scattering, SANS）实验，旨在探究PX3（其中X=Cl、Br、I）处理对配体封端磷化铟量子点（indium phosphide quantum dots, InP QDs）的影响，并对所得十二烷硫醇封端的InP@ZnS量子点（InP@ZnS QDs）进行表征。PX3处理可使该类材料的量子产率实现大幅提升，从5%提升至70%以上。此前在RB2420416工作中，我们已明确三氯化磷（PCl3）在该处理过程中的作用，本次研究将处理方法拓展至整个卤化磷家族，发现量子产率性能得到更大幅度提升，但磷化铟量子点的吸收/发射光谱发生了不同程度的位移。因此，本研究拟探索这些新型处理方法，并将其效果与三氯化磷的处理效果进行对比。衬度匹配小角中子散射测量在此过程中至关重要，可分别观测磷化铟核与封端配体烷基壳层的变化。由于经PX3处理后的磷化铟量子点在处理后至壳层包覆前稳定性极差，需开展原位测量。鉴于单次测量需覆盖较宽Q范围，优先选用SANS2D谱仪的束流时间。