title: Bismuth induced enhanced green emission from terbium ions and their complex in thin films.
abstract: Bismuth nanoparticles (NPs) have been prepared by the pulsed laser ablation technique using the third harmonics of a Nd-YAG laser. UV-absorption and TEM micrographs show Bi NPs of spherical shape with the average particle size ranging from 15 to 20 nm. These NPs were dispersed with Tb(3+) ions and their complex with salicylic acid (Sal) in polyvinyl alcohol to obtain thin films. The influence of Bi NPs on the emissive properties of Tb(3+) ions and the [Tb(Sal)3(phen)] complex has been studied by luminescence spectroscopy using 266 nm and 355 nm as excitation wavelengths. The luminescence intensity of Tb(3+) ions complexed with Sal in the thin polymer films increased significantly as compared to the Tb(3+) ions in the presence of Bi NPs on excitation at 355 nm. However, terbium ions in the case of the [Tb(Sal)3(phen)] complex together with NPs show an intense and extended emission spectrum in the 375-700 nm range for transitions arising from (5)D3 and (5)D4 levels to different (7)F(J) levels on 266 nm excitation. The luminescence enhancement has also been supported by lifetime measurements.
authors.affiliation: Laser and Spectroscopy Laboratory, Physics Department, Banaras Hindu University, Varanasi 221005, India. sbrai49@yahoo.co.in.
authors.forename: Gagandeep
authors.initials: G
authors.lastname: Kaur
authors.forename: Brijesh
authors.initials: B
authors.lastname: Kumar
authors.forename: R K
authors.initials: RK
authors.lastname: Verma
authors.forename: S B
authors.initials: SB
authors.lastname: Rai