Upconversion Emission in Tm/Er/Yb Co‐Doped Yttria Stabilized Zirconia Single Crystals

Abstract

Blue, green, and red emissions through upconversion and energy transfer processes are investigated as a function of the Tm3+ concentration in Tm/Er/Yb triply doped yttria stabilized zirconia (YSZ) crystals upon excitation at 980 nm. YSZ doped with 0.075–0.250 mol% Tm2O3, 1.50 mol% Er2O3, and 2.00 mol% Yb2O3 are prepared by the optical floating zone method, and confirmed to be in the cubic phase by X‐ray diffraction. The blue emission corresponds to the Tm3+ 1G4→3H6 transition, and is produced through a three‐photon process, whereas the green and red light are emitted through two‐photon processes from the Er3+ 2H11/2→4I15/2 and 4S3/2→4I15/2 transitions for green and the Er3+ 4F9/2→4I15/2 transition for red. However, interactions between the different lanthanide ions is a factor in determining the overall color of these triply doped crystals, and this is not simply a summation of the results from the singly doped systems, so this mechanism of energy transfer is discussed in detail. The CIE color chromaticity coordinates for the present samples under excitation at 980 nm approach (0.39, 0.55), which is in the yellow‐green region.

Luminescence properties of Eu2O3-doped ZrO2–Y2O3 single crystals

“…A more detailed description of the preparation procedures is presented in previous work. 4–8,26,27 We assume that the ratios of the elements in the crystals are the same as those in the starting mixtures, because the boiling points of each of the oxides are >1000 °C higher than the maximum temperature of the furnace during crystal synthesis. These are presented in tabular form in ESI† Table S1.…”