<br/>Detailed knowledge of charge carrier dynamics is important for research efforts on improving the performance of optoelectrical materials and devices. For example, colloidal semiconductor quantum dots have great potential for use in solar panels, but it remains a challenge to establish how carrier diffusion length and lifetime depend on nanoscale surface chemistry and morphology. It is, therefore, highly desirable to directly measure how photoexcited charge carriers diffuse in nanometer scale in real time. In this work, we investigate charge carrier dynamics in PbSe quantum-dot films infilled with aluminum oxide using time-resolved scattering scanning near-field optical microscopy with temporal resolution of 170 fs and tip-dependent spatial resolution of 25 nm. We will present near-field signals acquired at different delay times after confined pump-pulse illumination. The effect of surface capping groups on charge carrier dynamics will be discussed.

Charge carrier dynamics in PbSe quantum-dot films studied by femtosecond pump-probe scattering scanning near-field optical microscopy

2019 Fall National Meeting

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