Chemical Vapor Deposition Synthesis and Optical Properties of Nb₂O₅ Thin Films with Hybrid Functional Theoretical Insight into the Band Structure and Band Gaps

Abstract

NbO is an important material able to exist in many polymorphs with unique optical properties and morphologies that are dependent on the synthetic route. Here we report a novel ambient-pressure chemical vapor deposition route to NbO via aerosol-assisted chemical vapor deposition. The amorphous as-deposited films were annealed in air to obtain the the three most stable crystal structures: orthorhombic, tetragonal, and monoclinic. The films were thoroughly characterized for their material properties, and an in-depth study into the optical properties was carried out using state-of-the-art hybrid functional theory that allowed more insight into the optical properties of the materials.

Niobium Oxide Catalysts as Emerging Material for Textile Wastewater Reuse: Photocatalytic Decolorization of Azo Dyes

“…The electronic spectroscopy of diffuse reflectance made it possible to determine the band-gap energy required for the photo-promotion of one electron (see Figure 3b). The results indicated that Nb 2 O 5 presents a band gap of 3.1 eV, similar to the characteristic band gap of titanium dioxide photocatalysts [9,33], and at the low end of the Nb 2 O 5 bandgap values [34]. band gap of titanium dioxide photocatalysts [9,33], and at the low end of the Nb2O5 bandgap values [34].…”

“…The results indicated that Nb 2 O 5 presents a band gap of 3.1 eV, similar to the characteristic band gap of titanium dioxide photocatalysts [9,33], and at the low end of the Nb 2 O 5 bandgap values [34]. band gap of titanium dioxide photocatalysts [9,33], and at the low end of the Nb2O5 bandgap values [34]. The isotherm of nitrogen adsorption-desorption of Nb2O5 in Figure 4a presents a hysteresis loop characteristic of type IV isotherms, which is typical of mesoporous materials.…”

“…These results are in agreement with those reported by Wang et al [32] for commercial niobium oxide calcined at a temperature of 500 • C (S BET = 49.9 m 2 g −1 , V p = 0.12 cm 3 g −1 e d p = 9.6 nm), even when the niobium oxide precursor selected was different. band gap of titanium dioxide photocatalysts [9,33], and at the low end of the Nb2O5 bandgap values [34]. The isotherm of nitrogen adsorption-desorption of Nb2O5 in Figure 4a presents a hysteresis loop characteristic of type IV isotherms, which is typical of mesoporous materials.…”

Galore: Broadening and weighting for simulation of photoelectron spectroscopy

“…Implemented with ad-hoc scripts and spreadsheets, this method has already been used in many academic studies. [14][15][16][17][18] Known limitations and improvements…”

Silicon oxide-niobium oxide mixture films and nanolaminates grown by atomic layer deposition from niobium pentaethoxide and hexakis(ethylamino) disilane

“…Nb2O5 may be regarded as somewhat more conductive (electrically leaky) oxide compared to Ta2O5, due to its smaller band gap [23,32], and possibly larger stoichiometry deviations accompanied by oxygen vacancies. Despite the electrically relatively leaky character of niobium oxide, memristive structures [33] based on Nb2O5 have been proposed, either combined with Ta2O5 [34], deposited as single oxide layers [33][34][35][36][37][38], or layered alternately with other oxides such as TiO2 [39].…”