Thickness dependence of structural, optical and luminescence properties of BaTiO3 thin films prepared by RF magnetron sputtering

Abstract

BaTiO 3 thin films were deposited onto quartz substrates by RF magnetron sputtering. X-ray diffraction pattern showed the formation of BT thin films with a tetragonal structure with orientations along (101) plane. Average crystallite size increased from 12.52 to 14.87 nm as the film thickness increased from 207 to 554 nm. With the increase in film thickness, the structural disorder decreases and the crystalline quality of the films gradually improved. The film exhibited good adherence to the substrate and are crack free. X-ray photoelectron spectroscopy revealed the presence of barium, titanium and oxygen in BT film. An average transmittance of [80 % was observed for all the films. This high transmittance BT films in the visible region is suitable for various electro-optic applications. The transmittance spectra showed high UV-shielding properties. Optical band gap was found to decrease from 4.55 to 3.70 eV with increase of film thickness, whereas the refractive index was found to increase. The refractive index of the BT films can be tuned between 2.11 and 2.21 at 550 nm. The real and imaginary dielectric constants with increase in film thickness were investigated. The low dissipation factor of BT thin films makes it a promising material for frequency agile applications. The emission spectra of BT thin films consist of near band edge excitonic UV emission and defect related emission in the visible range. The PL emission bands in UV and visible region of BT thin films make them suitable for electro-optic devices and light emitters.

Investigation of barium titanate thin films as simple antireflection coatings for solar cells

“…The differences in optical properties of BTO of varied thickness correspond well to the discoveries reported in [24]. The refractive index increases with increasing thickness, although the differences between the thinner No.…”

“…BTO thin films are distinguished by broad UV Vis transparency and relatively high refractive index > 2.0 (589 nm) [6,24,25]. Therefore similarly to well-known high-refractive index oxides, e.g.…”

Type-II Band Alignment Enhances Unassisted Photoelectrochemical Water-Splitting Performance of the BaTiO3/CdS Ferroelectric Heterostructure Photoanode under Solar Light Irradiation

“…Apparently, the pure BTO nanostructures demonstrate two strong peaks at about 410 and 460 nm in the PL spectra, indicating the high recombination rate of the photogenerated charges in BTO nanostructures. 38 Nevertheless, compared to that of BTO nanostructures, the emission intensity of the BTO/CdS-10 heterostructures is apparently suppressed, indicating that the photogenerated charge carriers of BTO/CdS-10 heterostructures are separated effectively. The results of PL spectra further confirm that the improved PEC activity of BTO/CdS heterostructure photoanodes results from the effective separation of photoproduced charge carriers.…”

Current Rectification, Resistive Switching, and Stable NDR Effect in BaTiO3/CeO2 Heterostructure Devices

“…The observed trend of decrease in crystallite size and increase in strain on decreasing the films thicknesses is in accordance with previously observed findings. [32,33] According to these reports, the increase in crystallite size represents the growth of grains. As the film thickness increases coalescence of grains occurs which improves the crystallinity www.advelectronicmat.de of thin films and this improvement can be observed in XRD patterns.…”