Implementing Discrete Multistate Electrochemical Response to Colloidal Quantum Dots via Regulated Charge Transfer Pathways

Facilitating or impeding charge transfer pathways enables precise control over photoluminescence (PL) intensity in quantum dots (QDs), as the transfer of charge from QDs leads to PL quenching. In this study, we achieved discrete and reversible PL intensity modulation in QDs by using electrochemical methods. By designing QD-Prussian blue (PB) composites, we leveraged PB's electroswitchable properties, where applied voltages control the oxidation state of iron ions. These voltages regulate charge transfer pathways, modulating the interaction between the PB and QDs to achieve precise PL control. Additionally, the integration of engineered QD core-shell heterostructures enhanced the tunability of PL modulation. The synergistic interplay between applied voltages and QD heterostructures allowed for selective quenching or recovery of the PL intensity in two distinct QDs, enabling dual-color tunability. This multistate PL modulation provides a foundation for high-resolution displays and advanced optoelectronic devices.