Synthesis and studies of optical properties of Eu3+ doped Gd2O3 phosphor prepared via hydrothermal process

Abstract

Eu 3+ ion doped Gd 2 O 3 phosphors with varying concentrations were synthesized successfully by hydrothermal process. The XRD pattern of prepared samples was in good agreement with cubic system of pure Gd 2 O 3 (JCPDS No. 86-2477) with no extra phase. The TEM and HRTEM images also revealed the prepared samples are highly crystalline nanorods having the diameter in the range of 20 – 30 nm with different length. Vibrational modes are also studied using FT-IR Spectroscopy. Upon the emission at λ em = 612 nm, a broad absorption band observed around at 220 – 300 nm is due to overlap of O 2- to Eu 3+ charge transfer (CT) band, Gd 3+ to Eu 3+ CT band and host lattice absorption band and other weak bands observed at longer wavelength regions are attributed to the f-f transitions of the Eu 3+ ions. In the emission spectrum obtained by excitations at 258 nm, consists of the characteristic transition lines between Eu 3+ levels. The emission spectrum was dominated by the red 5 D 0  7 F 1 (612 nm) transition of the Eu 3+ ion which is an electric-dipole allowed transition and hypersensitive to the environment. The photoluminescence lifetime of the prepared samples are found to be 2.88 – 1.24 ms ranges.