Photon upconversion is a strategy for redistributing light energy, which takes one high energy photon and splits it into two lower energy photons, that can improve semiconductor-based devices from solar cells to photodetectors. One promising avenue towards achieving upconversion is to implement organic-based upconversion assisted by semiconductor nanocrystals. The mechanism of upconversion hinges on energy transfer across the nanocrystal surface to an organic molecule. Thus, understanding the nature of nanocrystalline surfaces and how these surfaces mediate the energy transfer process is crucial to implementing upconversion strategies in devices. The role that the ligand plays in transmitting energy as well as its impact on the surface chemistry of the nanocrystal is explored in several systems: PbS and Si nanocrystals paired with acene and perylenediimide molecules. Solution-based ligand exchange chemistry is found to induce the formation of surface-associated states which are long-lived and serve as an intermediate in the transfer process. This work offers insight into the interplay between nanocrystal surface functionalization and energy transfer efficiency.<br/>

Energy transfer controlled by the semiconductor nanocrystal to ligand interface

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.