Studies on Up-Conversion Photoluminescence Exhibited by Er3+-Doped Akermanite (Di-Calcium Magnesium Silicate) Phosphors

The preparation of di-calcium magnesium silicate Ca₂MgSi₂O₇ doped with 0.5, 1.0, 1.5, 2.0 and 2.5 mol.% of erbium (III) using a solid state reaction method is reported. An X-ray diffraction pattern obtained from the sample at optimum photoluminescence (PL) emission intensity exhibits a quite prominent resemblance with the crystallographic open database (COD) with entry 96-900-6449. This confirms the valid preparation of tetragonal akermanite with a P-4 21 m (113) space group. A 980 nm laser source is used as an excitation radiation for recording the PL emission spectra. The emission spectra exhibit two distinguished prominent peaks centered at 534 and 623 nm. These peaks are attributed to the ²H_11/2 → ⁴I_15/2 and ⁴F_9/2 → ⁴I_15/2 transitions of erbium (III) ions respectively. The sample with 2.0 mol.% of erbium (III) exhibits an optimum PL intensity, and beyond this the concentration quenching occurs. The thermoluminescence studies of the same sample suggest an existence of the near second order kinetics. Therefore, the sample could be a very good candidate in LED applications.