Study of optical behaviour of Eu3+ and Tb3+ doped zirconate perovskite phosphors prepared by molten salt technique

Abstract

This paper gives a keen insight of the study of spectroscopic and optical behavior of Eu3+ and Tb3+ doped calcium zirconate, barium zirconate and strontium zirconate perovskite phosphors synthesized by molten salt synthesis (MSS) technique. Here, the low temperature MSS technique uses molten chloride salt sodium chloride NaCl that increases solid–solid diffusion rate for creating an active reaction medium. These phosphors were subjected to sintering at a temperature of 950 °C with Eu3+ and Tb3+ ions doping concentration varying from 0 to 2 mol%. The Powder X-ray diffractometry technique was used to study of crystallographic behavior of synthesized phosphors. In order to study the morphological and topographical aspects, field-emission scanning electron microscopy and transmission electron microscopy analyses were done. The Fourier transform infrared analysis generates the fingerprint of the synthesized phosphors confirming the presence of all constituent elements. The photoluminescent (PL) characteristics of synthesized phosphors were studied on exciting CaZrO3:Eu3+, Tb3+ with 225 nm, BaZrO3:Eu3+, Tb3+ with 229 nm and SrZrO3:Eu3+, Tb3+ with 235 nm excitation wavelength. The PL emission spectra show variable emissions over a broad spectral region corresponding to 5D4–7F6, 5D4–7F5, 5D4–7F4 and 5D4–7F3 hypersensitive electronic transitions of Tb3+ ions along with 5D0–7F0, 5D0–7F1 and 5D0–7F2 induced electric dipole and magnetic dipole transitions of Eu3+ ions. These color tunable phosphors with increased PL output confirm their suitability for photonics, optoelectronics and display device applications.