High color rendering indices of white light-emitting diodes based on environmentally friendly carbon and AIZS nanoparticles

Solid-state white light-emitting diodes (WLEDs) based on carbon dots (CDs) have attracted broad attention due to their high brightness and environmental friendliness. However, the poor performance, including low efficiency and weak emission of red-emitting CDs, further hinder their application in WLED devices. Herein, we constructed one outstanding WLED device by combining carbon dots (blue emission and green emission) and Ag-In-Zn-S (AIZS) nanoparticles with red emission. Moreover, by adjusting the volume ratio of the three materials, the WLED showed a maximum color rendering index (CRI) of 97 and maintained a CRI value above 90 as the correlated color temperature (CCT) was tuned from 3387 to 8018 K. Meanwhile, the as-fabricated WLED devices showed excellent color rendering stability during the adjustment of working voltages from 3.0 V to 3.5 V. This work may provide one new avenue for the development of low-cost, environmentally friendly and high-performance CD phosphor-based WLEDs.