One-step synthesis of multi-colored ZnO nanoparticles for white light-emitting diodes.

ZnO nanoparticles (NPs) have been synthesized by a facile one-step synthesis method, and the emission color of the ZnO NPs can be tuned from orange to yellow, green, blue-green and blue. These ZnO NPs were used as phosphors to fabricate UV-pumped white light-emitting diodes (WLEDs). The color rendering index of the WLEDs is (0.31, 0.33), which is close to the standard white emission. The WLEDs have high correlated color temperature (6532 K) and Commission International de L'Eclairage (90.4). These results indicated that the multi-colored ZnO NPs have great application potential in lighting and display. • A facile one-step method was developed for the preparation of multi-colored ZnO NPs, and the emission color of the NPs can be tuned from orange to yellow, green, blue-green and blue. • The fluorescence emission of these NPs transitioned from orange to blue by adjusting their particle size from 10 nm to 4 nm, which was due to quantum confinement effect. • Based on their unique optical properties, multi-colored ZnO NPs were used to prepare the WLEDs. The CIE of the WLEDs was (0.31, 0.33), which was close to the standard white emission. In addition, the WLEDs had a high CCT (6532 K) and CIR (90.4). [ABSTRACT FROM AUTHOR]