Dopant concentration induced tuning of emission in Eu3+-doped zirconia nanoparticles

Abstract

Eu3+-doped zirconia has been considered an efficient phosphor material due to its multi-colour emissive photoluminescence properties. Tuning of emission colour is possible by changing the Eu3+-ions concentration and excitation wavelength. The influence of Eu3+-ions and excitation wavelength on the emission intensity, asymmetric ratio, CIE coordinates, and Judd-Ofelt parameters of the Eu3+-doped zirconia nanophosphors have been explored in this work. Ultra-fine nano-sized particles of pure tetragonal zirconia were observed when the samples were calcined under an argon atmosphere at 800 °C. The expansion and distortion of tetragonal zirconia has been confirmed from XRD and Raman Spectra of Eu3+-doped zirconia samples, respectively. The XPS analysis suggested elemental composition and incorporation of trivalent state of Eu-ions in Eu3+-doped zirconia sample calcined under argon calcination condition. Further, emission spectra of Eu3+-doped zirconia samples have been investigated at the excitation wavelength of 240 nm, 393 nm, and 463 nm. The emission spectra of 3 mol % and 6 mol % Eu3+-doped zirconia samples revealed several emission peaks in the range of 580–710 nm corresponding to the Eu3+-ions transition of 5D0 → 7Fj (=0 to 4). However, due to lower emission intensity, these transitions were not clearly visible up to 1 mol % Eu3+-ions. The CIE coordinates confirmed the tuning of emission colour in Eu3+-doped zirconia nanophosphor at different excitation wavelengths. The Judd-Ofelt parameters also suggested that the Eu3+-doped zirconia may be utilized for better optical gain. So, nano-sized Eu3+-doped zirconia phosphor materials may consider as a potential candidate for different luminescence applications.