Using triethanolamine and/or Na dopant to select the emission color (white or orange-red/NIR) of ZnO:Ca phosphors

ZnO:Ca,Na nanoparticles were synthesized by a wet-chemical-method. Na-dopant concentration was fixed to 16 mol%, while that for the Ca-dopant was 16 or 25 mol%. Triethanolamine (TEA) was employed as surfactant in the synthesis. XRD and SEM analyses demonstrated that the ZnO:Ca,Na nanoparticles had hexagonal phase and grain-like morphology. ZnO:Ca,Na nanoparticles synthesized with TEA produced cool-white light under 265 nm excitation, while these made without TEA generated intense orange-red/NIR emission bands under the same excitation wavelength. For reference purposes, ZnO:Ca nanoparticles were excited with 265 nm, and they solely produced blue/NIR emissions. When the ZnO:Ca,Na nanoparticles (synthesized with or without TEA) were excited with 365 nm, they emitted exclusively intense orange-red/NIR light. The emission-color was tuned from white to orange-red/NIR by changing the excitation wavelength from 265 to 365 nm.

Automated summary

ZnO:Ca,Na nanoparticles were synthesized using a wet-chemical method, with Na-dopant concentration fixed at 16 mol% and Ca-dopant concentration at either 16 or 25 mol%. Triethanolamine (TEA) was used as a surfactant during synthesis. XRD and SEM analysis confirmed the hexagonal phase and grain-like morphology of the nanoparticles. Under 265 nm excitation, ZnO:Ca,Na nanoparticles synthesized with TEA emitted cool-white light, while those made without TEA exhibited intense orange-red/NIR emission bands. Under 365 nm excitation, both types of ZnO:Ca,Na nanoparticles emitted exclusively intense orange-red/NIR light, with the excitation wavelength determining the emission color from white to orange-red/NIR.