Color tuning by varying driving frequency in an ultra-simple structure of metal/quantum dots/insulator

Achieving dynamic tunability of electroluminescence colors in quantum dot (QD) light-emitting devices has great application value for expanding their use in display, lighting, and optical communication. Fabricating QD light-emitting devices with a simple structure and easy color control remains challenging. This work realizes color tuning by varying driving frequency in an ultra-simple QD device with a structure of indium tin oxide/insulating polymer/red–green mixed QDs/Ag. It has been found that the ratio of red QDs (RQDs) to green QDs (GQDs) determines the primary color output of the device. The driving frequency can continuously adjust the relative intensities of the red and green emission components, achieving a color change from yellow-green to orange-yellow. This phenomenon originates from the different responses of red and green QDs to the driving frequency; that is, green QDs are more susceptible to the driving frequency than red QDs. This work proposes a method to tune the emission color of QD devices via frequency. It provides a new design concept and experimental basis for developing QD technologies with simple processes and tunable color.