I will describe our studies of PbS and PbSe nanocrystal nucleation and growth using a library of thiourea and selenourea derivatives. Depending on the chalcogenourea substitution pattern selected, we finely tune the kinetics of forming the metal chalcogenide over several orders of magnitude (&gt; 10^6). The flexible reactivity adjusts the steady state monomer concentration independent of the temperature or crystallization medium. Using this library we have studied the influence of monomer supply kinetics and temperature on the nucleation of PbS and PbSe <i>in situ, </i>using synchrotron X-ray scattering. These studies allow us to monitor crystal nucleation in real-time. Together with <i>in situ </i>absorption spectroscopy, we illustrate the surprising observation that nucleation is a relatively slow process that can occur over periods as long as minutes while producing a narrow size distribution. The origins of the narrow size distribution and the nucleation barrier will be discussed.

In situ studies of nanocrystal nucleation and growth

2019 Spring National Meeting

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