White light emitting devices with high color rendering index and electrically adjustable color temperature

Abstract

Herein, we report a rare earth-free white light emitting composite for applications in solid-state lighting, which is made up of carbon nitride (CN) and Mn2+-doped perovskite quantum dots (PQDs). The correlated color temperature (CCT) is adjustable from 18 088 to 2926 K by varying the ratio of the two components. When the PQDs content is 2.88%, the white light emitting diode (W-LED) based on the CN/PQDs composite shows a competitive color rendering index of 88, a CCT of 5737 K, and a chromaticity coordinate of (0.327, 0.33), which is close to the standard white light. The light conversion efficiency of the composite is around 10%, which is attributed to the high photoluminescence efficiencies of the two components and weak photon reabsorption between them. Moreover, the CCT can be tuned from 4750 to 7315 K by changing the repetition frequency of the electrical input.