WEB Surface Ligands in Quantum RodsThursday (24.09.2020) 10:10 - 10:40 Z: Special Symposia I Part of:
Semiconductor nanocrystal quantum dots represent an important class of chemically processible nanomaterials. Their use in photocatalytic energy conversion and light-emitting applications has garnered attention, as their moderate synthesis temperature and solution-processibility offer opportunities to address constraints on alternative technologies such as scalability. Additionally, by tuning the size, shape, and composition of colloidal nanocrystals, we can exploit quantum confinement effects, e.g., the size-tunable energy gap and discrete energy states. In this presentation, I will discuss new developments that enable (i) spatial separation of electrons and holes in heterostructure semiconductor nanocrystals for more efficient photocatalysis and (ii) the study of correlation between structures and visible light emission in core/shell quantum dots.
Examples of studied photocatalysts include PbSe/CdSe/CdS core/shell/shell nanocrystals with varying morphologies, e.g., pyramid and tetrapod. By growing metal tips at corners of the structures, we prepared semiconductor/metal nanojunction and used the nanomaterials as photocatalysts for reduction of various dyes and water-splitting reaction. Interestingly, the morphology change leads to drastic differences in photocatalysis. For light-emitting devices, we designed CdSe/CdS core/shell quantum dots and examined their electroluminescence properties as a function of core/shell dimensions. Our systematic investigation revealed that the shell thickness plays an important role in overall device performance.