Transport mechanism and IR structural characterisation of evaporated amorphous WO3 films

Antonaia, A.; Santoro, Mario; Fameli, G.; Polichetti, T.

doi:10.1016/s0040-6090(03)00011-7

Cited by 33 publications

(27 citation statements)

References 12 publications

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“…Such are obviously present within the films remaining from the chemical coloration process and from further aging upon exposure to normal ambient conditions. 34,68 We note that modes at 3234 and 3478 cm −1 were not observed here. Incorporation of additional O-H bonds during the intercalation process would drastically increase the oscillator amplitudes in the model DF obtained for the intercalated states.…”

Section: Hydroxyl Group Vibrationsmentioning

confidence: 53%

“…24,34 Water has known stretching and bending vibrations of its molecule near 1616, 2780, 3234, and 3478 cm −1 . The small-polarity bands at 1425 and 1620 cm −1 are assigned to hydroxyl group vibrations.…”

Section: Hydroxyl Group Vibrationsmentioning

confidence: 99%

“…[26][27][28][29] Previous SE reports discussed the polaron absorption range from the near-IR to the VIS spectral range. 11,19,30,31 Various approaches for physical lineshape analysis and polaron property assignment were employed such as oscillator approaches, [31][32][33][34] and parametric semiconductor models with rigorous treatment of their density of state functions. 33,35 Previous IRSE focused on uncolored amorphous tungsten oxide and electrochromic device performance for emittance modulation in the IR spectral region.…”

Section: Introductionmentioning

confidence: 99%

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Polaron and phonon properties in proton intercalated amorphous tungsten oxide thin films

et al. 2008

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We report on the evolution of the polaron and phonon mode properties in amorphous tungsten oxide thin films measured by spectroscopic ellipsometry in the infrared to ultraviolet spectral regions as a function of the intercalated proton density. A parametric physical model dielectric function is presented, which excellently describes the ellipsometry data over a large intercalated charge-density range. Upon increased amounts of intercalated charge we observe a strong increase in the polaron absorption in the visible spectral range, a decrease in the infrared W-O bond polarity, and an increase in the W = O bond polarity. Our findings support the oxygen-extraction model as the polaron formation mechanism in tungsten oxide in agreement with previous theoretical works based on first-principles pseudopotential calculations. We discuss and suggest polaron formation by oxygen-related defect generation as origin for the coloration mechanism in tungsten oxide. We further discuss possible evidence for very large effective mass of the polarons within the insulator-to-metal transition regime.

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Section: Hydroxyl Group Vibrationsmentioning

confidence: 53%

Section: Hydroxyl Group Vibrationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Polaron and phonon properties in proton intercalated amorphous tungsten oxide thin films

et al. 2008

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“…3(b), Bands at 600 and 1,000 cm −1 were associated with the W-O-W stretching modes. Obviously, these were only characteristic peaks of tungsten oxide, for there exists terminal stretching mode band W-Od at 863.27 cm −1 , corner-sharing vibration band υ-W-Ob at 774 cm −1 , and superoxide vibration band υW-O-O-W at 544 cm −1 [14,15]. The surfactant CTAB, therefore, was removed completely after microwave extraction.…”

Section: Xrd and Infrared Spectramentioning

confidence: 99%

Microwave synthesis of mesoporous WO3 doping with bismuth and photocatalytic oxidation of water to H2

Zou

Liu

et al. 2011

Korean J. Chem. Eng.

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Mesostructured tungstic acid was prepared from Na 2 WO 4 with protonated cation-exchange using a surfactant cetyltrimethyl ammonium bromine (CTAB) as the structure-directing agent under microwave radiation. The surfactant was removed by high-temperature calcination, microwave radiation extraction and Soxhlet extraction, respectively. The effects of these methods for removal of the surfactant were investigated in detail. XRD, TEM, FT-IR and UV-Vis were employed to characterize the mesostructured materials. The results showed that the microwave extraction and Soxhlet extraction were favorable to the synthesis of mesostructured tungstic oxide. Mesoporous structure was destroyed as the calcining temperature rising to 823 K. The mesoporous structure of WO 3 prepared by microwave radiation extraction had an average pore diameter of 3.4 nm and specific surface area of 120.46 m 2 ·g −1 . And also, the mesoporous materials WO 3 doping with Bi 2 O 3 displayed much higher photocatalytic activity than commercial Degussa P25 TiO 2 under visible light and UV irradiation.

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“…Basically, they can be categorized into two types, chalcogenide-based electrolytes (Ag-Se/S, Cu-Se/S, Ag-GeSe/S, Cu-Ge-Se/S [5][6][7][8][9]etc. ) and oxide-based electrolytes (WO 3 ) [25]. We will focus on chalcogenide based electrolytes in this paper.…”

Section: Theoretical Backgroundmentioning

confidence: 99%

Non-Volatile Memory Devices Based on Chalcogenide Materials

Wang¹

2011

Flash Memories

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Transport mechanism and IR structural characterisation of evaporated amorphous WO3 films

Cited by 33 publications

References 12 publications

Polaron and phonon properties in proton intercalated amorphous tungsten oxide thin films

Polaron and phonon properties in proton intercalated amorphous tungsten oxide thin films

Microwave synthesis of mesoporous WO3 doping with bismuth and photocatalytic oxidation of water to H2

Non-Volatile Memory Devices Based on Chalcogenide Materials

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