Tuning the electron transfer rates in near-infrared PbS quantum dots-anthraquinones complex by different chlorine-substituted

Abstract

The electron transfer (ET) from photoinduced quantum dot (QDs) to electron acceptors through a nanoscale interface plays a crucial part in the functionality and efficiency of QDs-photonic device. The driving force play a crucial part in the ET process of most QD-based system relying on the Marcus ET theory. However, there has rarely reports about tuning the driving force with substituents in acceptor molecules. Here, the ET process between near-infrared (NIR) PbS quantum dot (QDs) and different chlorine-substituted Anthraquinone (AQ) derivatives was studied via the femtosecond transient absorption spectroscopy. The ET process was gradually accelerated by adding chlorine atoms in these AQ molecules. Through the calculation of Marcus ET theory, the driving force of the complexes was gradually increased with the number of chlorine atoms substituted in AQ molecules, thus facilitating ET process. Our findings broaden the application of NIR PbS-organic compounds in photovoltaic devices.