Pressure tuning of electron transfer rate in near-infrared PbS-anthraquinone complexes

Abstract

The electron transfer (ET) process of near-infrared (NIR) quantum dots (QDs) is crucial to photonic system efficiency. Typically, chemical configurations are changed to tune the ultrafast ET rate. However, direct tuning of the ET rate in QD-molecular acceptor systems while maintaining the chemical configurations remains a challenge. To this end, high pressure can be used as a powerful external control knob. Herein, pressure tuning of the ultrafast ET rate in NIR lead sulfide (PbS)–anthraquinone (AQ) complexes was experimentally performed using in situ high-pressure ultrafast transient absorption spectroscopy. As pressure changes, ET lifetimes shorten. The results show that the promotional ET in the NIR range was assigned to the shortened distance between PbS and AQ under compression. This study thus indicates that pressure can effectively tune the ET rate and provides brand routes toward efficient NIR QD-based photonic applications.