Tuning Fluorescence Resonance Energy Transfer in Cadmium Telluride-Diketopyrrolopyrrole Hybrids via Bandgap Engineering

Fluorescence resonance energy transfer (FRET) has been proven to be an efficient sensitization method to construct broad-spectrum responsive organic–inorganic hybrid systems for efficient conversion and utilization of solar energy. To investigate the effect of the inorganic material bandgap on FRET dynamics and mechanism, we have constructed a series of cadmium telluride (CdTe) quantum dot (QD)-diketopyrrolopyrrole (DPP) hybrids via QD bandgap engineering. Steady-state and transient spectroscopy revealed that a fast and efficient FRET process was proceeded in these systems. Via controlling the spectral overlap degree between them by adjusting the CdTe QD size, the FRET dynamics and direction could be controlled effectively. A large spectral overlap integral between the emission of the donor and the absorption of the acceptor is crucial for realizing efficient and rapid FRET. These insights gained from this study contribute to the advancement of QD–dye nanocomposite materials, facilitating their application in a wide range of fields.