Effect of preparation conditions on the optical and thermochromic properties of thin films of tungsten oxide

S. M.A. Durrani; E. E. Khawaja; M. A. Salim; M. F. Al-Kuhaili; A. M. Al-Shukri

doi:10.1016/S0927-0248(01)00090-3

Effect of preparation conditions on the optical and thermochromic properties of thin films of tungsten oxide

S. M.A. Durrani^*, E. E. Khawaja, M. A. Salim, M. F. Al-Kuhaili, A. M. Al-Shukri

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

62 Scopus citations

Abstract

Thin films of tungsten oxide have been prepared by thermal evaporation. The effect of preparation conditions (heating of substrates and oxygen environment) on the optical constants (n and k) of the films has been studied. Satisfactory derivation of n and k from the measured normal incidence transmittance of the films was achieved. It was found that (a) both n and k have larger values for films deposited on heated substrates than for those deposited on unheated substrates, and at a given substrate temperature, (b) both n and k have smaller values for films deposited in the oxygen atmosphere than those deposited without an introduction of oxygen in the chamber. Thermochromic colouration of the films was carried out by annealing the films in vacuum. The annealing of the films produced significant loss in the oxygen content (measured by X-ray photoelectron spectroscopy) and modulation of the transmittance for the films deposited on unheated substrates with or without the oxygen environment and films deposited on heated substrates with the oxygen. The loss in the oxygen content and the modulation of transmittance, however, were very small for films deposited on heated substrates without the oxygen. For annealed films, satisfactory derivation of n and k was achieved for films deposited on unheated substrates, while for films deposited on heated substrates this was not possible. This study revealed that upon annealing the optical properties of the films prepared in the oxygen environment were mainly absorptance-modulated, and those of the films without the oxygen were reflectance-modulated.

Original language	English
Pages (from-to)	313-325
Number of pages	13
Journal	Solar Energy Materials and Solar Cells
Volume	71
Issue number	3
DOIs	https://doi.org/10.1016/S0927-0248(01)00090-3
State	Published - 15 Feb 2002

Bibliographical note

Funding Information:
This work is part of an internal project # CAPS1202, supported by the Research Institute of King Fahd University of Petroleum and Minerals.

Keywords

Thermal evaporation
Thermochromic properties
WO films

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Renewable Energy, Sustainability and the Environment
Surfaces, Coatings and Films

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10.1016/S0927-0248(01)00090-3

Cite this

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title = "Effect of preparation conditions on the optical and thermochromic properties of thin films of tungsten oxide",

abstract = "Thin films of tungsten oxide have been prepared by thermal evaporation. The effect of preparation conditions (heating of substrates and oxygen environment) on the optical constants (n and k) of the films has been studied. Satisfactory derivation of n and k from the measured normal incidence transmittance of the films was achieved. It was found that (a) both n and k have larger values for films deposited on heated substrates than for those deposited on unheated substrates, and at a given substrate temperature, (b) both n and k have smaller values for films deposited in the oxygen atmosphere than those deposited without an introduction of oxygen in the chamber. Thermochromic colouration of the films was carried out by annealing the films in vacuum. The annealing of the films produced significant loss in the oxygen content (measured by X-ray photoelectron spectroscopy) and modulation of the transmittance for the films deposited on unheated substrates with or without the oxygen environment and films deposited on heated substrates with the oxygen. The loss in the oxygen content and the modulation of transmittance, however, were very small for films deposited on heated substrates without the oxygen. For annealed films, satisfactory derivation of n and k was achieved for films deposited on unheated substrates, while for films deposited on heated substrates this was not possible. This study revealed that upon annealing the optical properties of the films prepared in the oxygen environment were mainly absorptance-modulated, and those of the films without the oxygen were reflectance-modulated.",

keywords = "Thermal evaporation, Thermochromic properties, WO films",

author = "Durrani, {S. M.A.} and Khawaja, {E. E.} and Salim, {M. A.} and Al-Kuhaili, {M. F.} and Al-Shukri, {A. M.}",

note = "Funding Information: This work is part of an internal project # CAPS1202, supported by the Research Institute of King Fahd University of Petroleum and Minerals.",

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doi = "10.1016/S0927-0248(01)00090-3",

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T1 - Effect of preparation conditions on the optical and thermochromic properties of thin films of tungsten oxide

AU - Durrani, S. M.A.

AU - Khawaja, E. E.

AU - Salim, M. A.

AU - Al-Kuhaili, M. F.

AU - Al-Shukri, A. M.

N1 - Funding Information: This work is part of an internal project # CAPS1202, supported by the Research Institute of King Fahd University of Petroleum and Minerals.

PY - 2002/2/15

Y1 - 2002/2/15

N2 - Thin films of tungsten oxide have been prepared by thermal evaporation. The effect of preparation conditions (heating of substrates and oxygen environment) on the optical constants (n and k) of the films has been studied. Satisfactory derivation of n and k from the measured normal incidence transmittance of the films was achieved. It was found that (a) both n and k have larger values for films deposited on heated substrates than for those deposited on unheated substrates, and at a given substrate temperature, (b) both n and k have smaller values for films deposited in the oxygen atmosphere than those deposited without an introduction of oxygen in the chamber. Thermochromic colouration of the films was carried out by annealing the films in vacuum. The annealing of the films produced significant loss in the oxygen content (measured by X-ray photoelectron spectroscopy) and modulation of the transmittance for the films deposited on unheated substrates with or without the oxygen environment and films deposited on heated substrates with the oxygen. The loss in the oxygen content and the modulation of transmittance, however, were very small for films deposited on heated substrates without the oxygen. For annealed films, satisfactory derivation of n and k was achieved for films deposited on unheated substrates, while for films deposited on heated substrates this was not possible. This study revealed that upon annealing the optical properties of the films prepared in the oxygen environment were mainly absorptance-modulated, and those of the films without the oxygen were reflectance-modulated.

AB - Thin films of tungsten oxide have been prepared by thermal evaporation. The effect of preparation conditions (heating of substrates and oxygen environment) on the optical constants (n and k) of the films has been studied. Satisfactory derivation of n and k from the measured normal incidence transmittance of the films was achieved. It was found that (a) both n and k have larger values for films deposited on heated substrates than for those deposited on unheated substrates, and at a given substrate temperature, (b) both n and k have smaller values for films deposited in the oxygen atmosphere than those deposited without an introduction of oxygen in the chamber. Thermochromic colouration of the films was carried out by annealing the films in vacuum. The annealing of the films produced significant loss in the oxygen content (measured by X-ray photoelectron spectroscopy) and modulation of the transmittance for the films deposited on unheated substrates with or without the oxygen environment and films deposited on heated substrates with the oxygen. The loss in the oxygen content and the modulation of transmittance, however, were very small for films deposited on heated substrates without the oxygen. For annealed films, satisfactory derivation of n and k was achieved for films deposited on unheated substrates, while for films deposited on heated substrates this was not possible. This study revealed that upon annealing the optical properties of the films prepared in the oxygen environment were mainly absorptance-modulated, and those of the films without the oxygen were reflectance-modulated.

KW - Thermal evaporation

KW - Thermochromic properties

KW - WO films

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SN - 0927-0248

VL - 71

SP - 313

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JO - Solar Energy Materials and Solar Cells

JF - Solar Energy Materials and Solar Cells

IS - 3

ER -

Effect of preparation conditions on the optical and thermochromic properties of thin films of tungsten oxide

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

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