Spectroelectrochemistry of Colloidal CdSe Quantum Dots

Abstract

Solution-phase spectroelectrochemistry was used to study electron injection into colloidal CdSe quantum dots (QDs) with sizes ranging from 3.4 to 11.1 nm in tetrahydrofuran (THF). The absorbance and photoluminescence of the QDs were monitored in response to both charging and discharging cycles, and the optical changes were reversible on a timescale of minutes. Bleaching of the QD 1S3/2h1Se exciton state was used to determine the conduction band energy levels. We found that the negative trion state was stable in THF for hours under an applied cathodic potential. Both the degree of bleaching and the recovery of the exciton state depended on the applied potential. Based on the current and charg..