Enhancement in red emission at room temperature from europium doped ZnO nanowires by 1,10 phenanthroline-europium interface induced resonant excitations

Abstract

We show that europium doped ZnO nanowires after surface modification with organic ligand, 1,10 phenanthroline (phen) leads to strong red emission at 613 nm which is a characteristic emission from the atomic levels of Eu3+. Surface modification with phen leads to formation of phenanthroline-europium interface on the surface of the nanowires due to attachment of Eu3+ ions. After an optimized surface modification with phen, intensity of both the UV emission (band edge) and red emission improved by two orders of magnitude at room temperature. We observed multiple energy transfer pathways to the energy levels of Eu3+ ions through the phenanthroline-europium interface, which found to be very effective to the significant enhancement of emission from the dopant Eu3+. This study shows a new insight in to the energy transfer process from phen to the europium doped ZnO system.

Superhydrophobic cotton fabrics based on ZnO nanoparticles functionalization

“…By analyzing the spectra corresponding to functionalized samples, it is possible to observe the appearance of a peak at 1558 cm −1 and other at 1400 cm −1 relative to the stretching vibration of C=O group [37][38][39], which can be associated with ZnO NPs precursor (zinc acetate), proving the presence of ZnO on the fabric. In these spectra, it is also possible to observe two new small peaks at 667 cm −1 and 609 cm −1 , which are usually attributed to Zn-O stretching vibration, confirming the presence of ZnO NPs in the cotton fabrics [40]. The presence of ZnO in the structure is certain and can be attained by the alteration of the material by differentiation of new bands, which previously did not exist.…”

Comparison of 4d- and 4f-Metal Chemistry through Spectroscopic Analysis of 1,10-Phenanthroline Coordination Compounds in Solution and Embedded Polystyrene Beads

“…The emission spectrum of the free phen ligand displayed a broad spectrum in the range 325–450 nm with a fine vibrational structure that consists of four moderately narrow peaks at 349, 363 (peak maximum), 380, and 403 nm following excitation at 296 nm (Figure ). These peaks were attributed to the π* → π transitions resulting from the ligand emission. , The excitation peak maximum (296 nm) of the free phen resulting from monitoring the emission at 363 nm was shifted to 291 nm (blue-shifted) and 299 nm (red-shifted) when coordinated to Ru 2+ and Eu 3+ ions, respectively (Figure ). The shifts in the absorption and excitation peak maxima of the Eu 3+ (red-shift) and Ru 2+ (blue-shift) suggest differences in the electronic properties as expected for 4 d and 4 f metal ions. , …”

“…These peaks were attributed to the π* → π transitions resulting from the ligand emission. 70,73 The excitation peak maximum (296 nm) of the free phen resulting from monitoring the emission at 363 nm was shifted to 291 nm (blue-shifted) and 299 nm (red-shifted) when coordinated to Ru 2+ and Eu 3+ ions, respectively (Figure 3). The shifts in the absorption and excitation peak maxima of the Eu 3+ (red-shift) and Ru 2+ (blue-shift) suggest differences in the electronic properties as expected for 4d and 4f metal ions.…”

Formation and optical characteristics of ZnO:Eu/ZnO nanowires grown by sputtering-assisted metalorganic chemical vapor deposition

“…There have been several reports on red luminescence from Eu 3+ ions in Eu-doped ZnO nanostructures including thin films, [10][11][12][13][14][15] nanocrystals [16][17][18][19] and nanorods/NWs. [20][21][22] We focus on ZnO NW structures as a host configuration to improve the crystal quality compared with conventional thinfilm configurations, and in this way increase the luminescence intensity. The improvement in crystal quality is the result of relaxation of the strain energy by the lattice mismatch originating from the unique boundary conditions induced by their finite lateral dimensionality.…”