Influence of manganese ions in the band gap of tin oxide nanoparticles: structure, microstructure and optical studies

Abstract

This paper presents the joint effect of strain-and doping-induced band gap change in Sn 1Àx Mn x O (0 # x # 0.05) nanoparticles. In addition, an effort was made to understand the effect of Mn doping on the structural and optical properties of SnO 2 . X-ray diffraction analysis showed a tetragonal structure and the unit cell volume decreased slightly with Mn 4+ content. The Mn:SnO 2 are spherical shaped particles with a size ranging from 7.7 to 13.8 nm as calculated by transmission electron microscopy, Scherrer's formula and Willamson-Hall plot. X-ray photoelectron spectroscopy showed clear evidence for tetragonal coordinated high-spin Mn 4+ ions occupying the lattice sites of Sn 4+ in the SnO 2 host. Electron energy loss spectroscopy further confirmed composition and oxidation states of Sn 4+ and Mn 4+ ions. Manganese doping increased the band gap of SnO 2 from 4 eV to 4.40 eV with Mn 4+ concentration. Variation in band gap energy was attributed to the increasing lattice strain with Mn content and the charge transfer transitions between Mn 4+ ions and conduction/valence bands of SnO 2 . Three photoluminescence emission bands observed at 320, 360 and 380 nm, when excited at 250 nm, proved Mn:SnO 2 to exhibit good optical emission and to have potential application in nanoscale optoelectronic devices.

Influence of Mn Doping on the Properties of Tin Oxide Nanoparticles Prepared by Co-Precipitation Method

“…These imperfections may incorporate oxygen vacancies inside the composite matrix. This happened due to the existence of dangling bonds inside the SnO 2 nanoparticles [38]. The free-exciting recombination process had caused UV emission near the band edge.…”

Photoluminescence of CdZnTe thick films obtained by close-spaced vacuum sublimation

“…analogously as that was done in Ref. [30]. The values of Zn concentration in Cd 1 À x Zn x Te thin films were determined by Vegard's law using lattice parameter calculated from position of (1 1 1) XRD line.…”

“…Obtained X-ray patterns were used for phase analysis as well as for determination of the microstresses from the broadening of XRD peaks [17,30]. Namely, the calculation of stress values was performed using the equation ε¼β/(4tanΘ), where β-instrumental broadening of the diffraction peak and Θ-diffraction angle, i.e.…”

A facile bio-replicated synthesis of SnO2 motifs with porous surface by using pollen grains of Peltophorum pterocarpum as a template

“…By considering the peak positions, shape and relative distance (4 eV) SnO 2 phase can be confirmed. This conclusion was made in comparison with our earlier EELS data on pure SnO 2 reported already [33]. The third region of 540e560 eV is the extended fine structure in the oxygen ionization edge and this feature can be attributed to the scattering of neighbour atoms of SnO 2 structure.…”