Upconversion luminescence of Er3+ doped Y2O3 and Gd2O3 nanophosphors Online publication date: Fri, 20-Nov-2020
by Tran Kim Anh; Dang Van Thai; Vu Thi Thai Ha; Wieslaw Strek; Le Quoc Minh
International Journal of Nanotechnology (IJNT), Vol. 17, No. 7/8/9/10, 2020
Abstract: The luminescence process and mechanism of Er3+ doped Y2O3 and Gd2O3 nanophosphors are investigated with focus on their upconversion luminescence properties. Here the strong up-conversion (UC) emissions of both Y2O3:Er3+ nanoparticles prepared by combustion with EDTA and Gd2O3:Er3+ nanospheres synthesised by multistep chemical reaction using urea have been measured at room or low temperatures. The downward-conversion luminescence spectra in visible and near infrared region have been assigned from the transitions in the energy level system of Er3+ion. For Y2O3:Er3+nanoparticles, the upconversion luminescent intensity depends on excitation power at 980 nm have properly indicated the two photon process which are the calculated slope values of main transitions in Er3+ions: 2H11/2-4I15/2, 4S3/2-4I15/2and 4F9/2-4I15/2 are 2.07, 1.72, 1.87 (0.5% Er) and 2.32, 1.82 and 2.07 (Er 1.0%) respectively. The integral intensity of the red band is smaller than that of the green band in the upconversion emission of nanoparticles Y2O3 doped with Er3+ with 0.50, 1.00 and 1.50%. However it was the integral intensity of red emission bands that dominated in Gd2O3: 1% Er3+. The lifetimes of the band in green colour peaked at 562 nm upon excitation at 380 nm in Y2O3:Er3+ with 0.50, 1.00 and 1.50%, and have shown the two sequent time decay processes, the shorter and the longer, both in millisecond scale, 0.14 ms (0.5%); 0.28 ms (1.00%) and 0.13 ms (1.50%) and 4.49 ms (0.5%); 6.89 ms (1.00%) and 5.16 ms (1.50%), respectively. For the nanoparticles Gd2O3: 1% Er the intensity decrease of the upconversion emission peaked at 562 nm with only a single process with a decay time of 1.24 ms. Both nanophosphors Y2O3 and Gd2O3 doped with Er3+ are promising materials to develop multifunctional units for medical applications.
Online publication date: Fri, 20-Nov-2020
If you are not a subscriber and you just want to read the full contents of this article, buy online access here.Complimentary Subscribers, Editors or Members of the Editorial Board of the International Journal of Nanotechnology (IJNT):
Login with your Inderscience username and password:
Want to subscribe?
A subscription gives you complete access to all articles in the current issue, as well as to all articles in the previous three years (where applicable). See our Orders page to subscribe.
If you still need assistance, please email firstname.lastname@example.org