Bandgap engineering by tuning particle size and crystallinity of SnO2–Fe2O3 nanocrystalline composite thin films

Abstract

We report the structural and optical properties of xSnO2–yFe2O3 nanocrystalline composite thin films. SnO2 and Fe2O3 exhibit strong phase separation instability and their particle size and crystallinity are tunable by changing their composition and annealing temperature. The bandgap for these composites continuously increases from 2.3 to 3.89 eV. We discuss the increasing bandgap values in terms of the quantum confinement effect manifested by the decreasing size of Fe2O3 crystallites. The method provides a generic approach for the tuning of the bandgap in nanocomposite systems.

An Experimental and Computational Study of β-AgVO3: Optical Properties and Formation of Ag Nanoparticles

“…Besides that, it is known that quantum confinement in semiconductor NPs increase the bandgap energy 54 . An analysis of the results of Table 1 In order to get an insight about the optical properties of the prepared samples, PL measurements were carried out.…”

Effect of Calcination on the Electrical Properties and Quantum Confinement of Fe2o3 Nanoparticles

“…'  here) , m e * and m h * are the effective masses of electron and hole respectively, e is the electronic charge and h is the Planck's constant. We have used the '  value observed at 40 o C temperature and 1 kHz frequency and a value of 12.5/m o (where m o is the electron rest mass) [14] for the bracketed item in relation (4).…”

Microstructure, Mössbauer, and Optical Characterizations of Nanocrystalline α-Fe2O3 Synthesized by Chemical Route

“…Fu et al [25] reported that the α-Fe 2 O 3 nanoparticles exhibited n-type semiconducting (SC) properties under ambient conditions with a band gap of 2.2 eV. Sahana et al [26] reported that the band gap for α-Fe 2 O 3 nanoparticle was 2.3 eV, and bandgap increases by the decreasing size of Fe 2 O 3 crystallites which was manifested in terms of the quantum confinement effect.…”

“…All experimental patterns are fitted very well and the structure and microstructure parameters like crystallite size, lattice parameters, oxygen concentration, and displacement of oxygen atoms in α-Fe 2 O 3 lattice are obtained from the Rietveld analysis [22][23][24][25][26].…”