Perspective Chapter: Electrochromic Efficiency in TixMe(1-x)Oy Type Mixed Metal-Oxide Alloys

Abstract

Energy-effective smart windows, mirrors, display devices, and automobile sunroofs have been considered as applications of electrochromic materials. This chapter focuses on the electrochromic behavior of Ti-based mixed metal oxides. Transition metal oxides such as Titanium oxide (TiO2) have been used as promising electrochromic material for this purpose since a smart window contains solid electrolyte and electrochromic material layers (commonly metal oxide layers) sandwiched between transparent conductive layers. However, relatively few publications studied the possible advantages (higher colorization efficiency) of the mixtures of different metal oxides as electrochromic material. This chapter aims to assess the results of investigations of Ti-based multicomponent materials (TiO2-WO3, TiO2-V2O5, TiO2–MoO3, TiO2–SnO2) showing enhanced electrochromic properties compared to the pure TiO2.

Full text

Chapter
Perspective Chapter:
Electrochromic Efficiency in
Ti
x
Me
(1-x)
O
y
Type Mixed
Metal-Oxide Alloys
Zoltán Lábadi, Noor Taha Ismaeel, Peter Petrik and
Miklós Fried
Abstract
Energy-effective smart windows, mirrors, display devices, and automobile sunroofs
have been considered as applications of electrochromic materials. This chapter focuses
on the electrochromic behavior of Ti-based mixed metal oxides. Transition metal oxides
such as Titanium oxide (TiO
2
) have been used as promising electrochromic material for
this purpose since a smart window contains solid electrolyte and electrochromic mate-
rial layers (commonly metal oxide layers) sandwiched between transparent conductive
layers. However, relatively few publications studied the possible advantages (higher
colorization efficiency) of the mixtures of different metal oxides as electrochromic
material. This chapter aims to assess the results of investigations of Ti-based
multicomponent materials (TiO
2
-WO
3
,TiO
2
-V
2
O
5
,TiO
2
–MoO
3
,TiO
2
–SnO
2
) showing
enhanced electrochromic properties compared to the pure TiO
2
.
Keywords: mixed metal oxides, reactive sputtering, electrochromic materials,
coloration efficiency, TiO
2
1. Introduction
Air conditioning, heating, and ventilation in buildings account for 30–40% of the
world’s energy consumption [1]. Improving the thermal and optical properties of
windows can reduce a building’s energy deficit by up to 40% [2]. Therefore, it is
important to develop technologies that dynamically control the transparency of win-
dows to reduce energy consumption in buildings. Electrochromic windows are among
the favorable solutions to this problem, as they change their light-transmitting prop-
erties when exposed to DC bias [3–5]. Dynamic control of sunlight transmission pro-
vides an opportunity to reduce energy and lighting costs by 20–50% for commercial
buildings [1, 6, 7]. The active components of such electrochromic window technolo-
gies are metal oxide layers or organic films [3, 8–11] that display electrochromism, a
phenomenon where a material changes its optical properties upon charge injection or
1

extraction. There are many types of such as Titanium Dioxide (TiO
2
), Chromium
Oxide (CrO), Niobium Pentoxide (Nb
2
O
5
), Tin Oxide (SnO
2
), Nickel Oxide (NiO),
Iridium Oxide (IrO
2
), Tungsten Trioxide (WO
3
), Molybdenum Trioxide (MoO
3
), and
Vanadium Oxide (V
2
O
5
) [12–19].
The color change caused by applied direct electric current (DC) is the
definition of electrochromic phenomena. Transition metal (Tungsten and Molybdenum)
oxide films are the most widely investigated materials for this purpose. The solid-state
electrochromic device consists of the electrochromic, charge storage, and electrolyte
layers sandwiched between transparent conducting electrodes (TCO).
Electrochromic properties, mainly coloration efficiency, kinetics of the coloration-
bleaching process, and cyclic durability of metal oxides strongly depend on its com-
positional morphological, structural, and characteristics. It is important to study the
effect of deposition techniques and growth parameters. Important parameter for EC
films is the coloration efficiency (CE) which refers to the optical density change
(ΔOD) at a certain wavelength induced when a unit area is injected with charge (Q
d
).
The CE is calculated using the following equation, and ΔOD is equal with the change
of transmittance according to the Beer–Lambert law:
CE λðÞ¼ΔOD=Qd ¼log Tb=Tc=Qd
ð(1)
where T
b
is the transmittance of the bleached state, T
c
is the transmittance of the
colored state, and Q
d
is the density of the charge inserted into or extracted from the
electrochromic material (cm
2
/C, square centimeter per Coulomb). CE has been calcu-
lated by specific absorption wavelength (λ) and the transmittances (T
b
and T
c
) have
been dependent on this wavelength. The coloring process evaluated the power
requirements by CE and the CE was clear about the electronic efficiency of the ECDs.
The result of the CE was presented by a plot of optical change vs. charge density
which fitted the linear part of the graph, or alternatively, the relative transmission vs.
input charge curves were plotted and CE values can be determined from the fitted
exponential curves, see Figure 1 [20].
Due to possible electron transitions between two sets of electrons, the EC effect
can be more pronounced in mixed oxides. Despite this, only a small number of studies
can be read about the possible optimization of the EC parameters in mixed oxide-type
films. The purpose of this review is to summarize the results of such investigations on
Ti-based mixed oxide layers.
2. “Pure”metal oxides
2.1 Tungsten oxide (WO
3
)
The most widely studied EC oxide is Tungsten oxide (WO
3
), and films of this
material have been prepared by several different methods. “Traditional”thin film-
making methods include for instance: chemical methods (spin-coating, sol–gel depo-
sition, chemical bath deposition, Langmuir–Blodgett technique, etc.), chemical and
physical vapor deposition, electrochemical methods (anodization, plating), see Ref.
[10] and references therein. Examples of physical vapor deposition: sputtering
[20–22], thermal evaporation [23–27], and pulsed laser deposition [28, 29].
2
Titanium Dioxide –Uses, Applications, and Advances

Figure 1.
Relative transmission vs. input charge curves at five wavelengths for a pure WO3 sample (a), for a WO3-MO3
(Mo-60.3%) mixed sample (b), and for a pure MoO3 sample (c). CE values were determined from the fitted
exponential curves (ExpFit). From Ref. [20].
3
Perspective Chapter: Electrochromic Efficiency in Ti
x
Me
(1-x)
O
y
Type Mixed…
DOI: http://dx.doi.org/10.5772/intechopen.1008197

Specific examples of chemical methods are the following: chemical vapor deposi-
tion [30–32] and related spray pyrolysis [33–37], and many investigations based on
chemical methods to make W oxide films [38–40]. Other researchers used electrode-
position [40, 41], anodization [42–45], and electrophoretic deposition [46]. The CE
was found to be more than 60 cm
2
/C in the red region in most cases [10, 47].
2.2 Molybdenum oxide (MoO
3
)
Electrochromic Mo oxide (MoO
3
) shows similar behavior to W oxide, and wide-
spread studies used films prepared by evaporation [48, 49], chemical vapor deposition
[50], wet chemical techniques [51, 52], and electrodeposition [53]. CE was measured
34 cm
2
/C at 630 nm [49].
2.3 Titanium oxide (TiO
2
)
EC properties of Ti oxide (TiO
2
) were also extensively studied prepared by the
following methods: sputtering [54], chemical vapor deposition [55], and spray pyrolysis
[56, 57], various wet chemical techniques [58–60], and anodization [61–63]. The CE was
25 cm
2
/C for reactive DC magnetron sputtering deposited TiO
2
films. TiO
2
films have
been also deposited by different chemical techniques and those films were used to deter-
mine the CE values, and verified that such films can show the same values of CE [54].
Different deposition methods as radio frequency (RF) reactive sputtering tech-
nique [64] and thermionic vacuum arc method have been reported for TiO
2
[65].
3. Mixed oxides
3.1 TiO
2
-WO
3
TiO
2
and WO
3
core/shell nanorod arrays were prepared by the combination of
hydrothermal and electrodeposition methods, in the work of Cai et al. [66]. The
deposition solution was prepared by dissolving Na
2
WO
4
salt in deionized water (con-
centration: 12.5 mM) and adding hydrogen peroxide to the solution maintaining a
concentration ratio of 3 with sodium tungstate. Fluorine-doped tin oxide (FTO) glass
coated with TiO
2
nanorod array was used as the deposition electrode. Remarkable
enhancement of the electrochromic properties was found in the nano-array films.
Significant optical modulation (57.2% at 750 nm, 70.3% at 1800 nm, and 38.4% at
10 μm), excellent cycling performance (65.1% after 10,000 cycles) and high CE
(67.5 cm
2
C1 at 750 nm), fast switching speed (2.4 s and 1.6 s), have been achieved
for the core/shell nanorod arrays. Since a larger surface area for charge-transfer
reactions was available for ion diffusion, the improved electrochromic properties were
mainly attributed to the core/shell structure and the porous space among the nanorod
arrays. The presented data made the TiO
2
and WO
3
core/shell nanorod arrays a
promising material for practical electrochromic purposes.
Patil et al. [67] have used spray pyrolysis technique at 525°C to deposit TiO
2
-doped
WO
3
thin films onto FTO coated conducting glass substrates. Tungsten trioxide
(WO
3
) and titanyl acetylacetonate (C
10
H
14
O
5
Ti) were used as base materials for the
deposition of TiO
2
-doped WO
3
thin films. The WO
3
powder was dissolved in liquid
ammonia at 80°C to obtain an ammonium tungstat solution. The titanyl acetyl
acetonate powder (C
10
H
14
O
5
Ti) was mixed with methanol separately at room
4
Titanium Dioxide –Uses, Applications, and Advances

temperature. The two solutions were stirred in different volume % to form a homo-
geneous 100 ml precursor solution, at pH = 9. Volume percentage of the dopant varied
between 13% and 38% v/v of TiO
2
. (For greater than 38% doping percentage of TiO
2
in WO
3
homogeneous solution could not be formed and precipitation dominates.) The
thin film samples were uniform, transparent, and strongly adhesive to the substrates.
With the help of chronoamperometry (CA), cyclic voltammetry (CV) and
chronocoulometry (CC) techniques, electrochromical properties of TiO
2
-doped WO
3
thin films have been studied. They concluded that within the studied range, TiO
2
doping enhances the electrochromic performance of WO
3
and samples exhibited
increasingly high reversibility with TiO
2
doping concentrations.
Dhandayuthapani et al. [68] reported a low-temperature making of WO
3
/TiO
2
films via a combined chemical bath deposition and nebulized spray deposition
method. The WO
3
layer influenced the compositional, morphological, structural, and
electrochemical properties of TiO
2
films. The layered WO
3
nanoplates on the TiO
2
layer significantly improved the current density of the TiO
2
films. The electrochemical
investigation of the annealed WO
3
/TiO
2
films displayed a CE of 128.3 cm
2
C
1
, optical
modulation (ΔT) of 78%, and reversibility of 77.2%. Excellent durability for
1000 cycles was exhibited with a fast response of 6 s for coloration and bleaching. This
enhancement could be explained by the interconnected nanoplate bundles which
accommodate more charges and facilitate faster charge transport. The complemen-
tarity of the WO
3
–TiO
2
layers leads to efficient electrochromic character [68].
In a recent work, Ashok Reddy et al. [69] investigated the preparation of Titanium
dioxide (TiO
2
) nanorods/Tungsten oxide (WO
3
) hybrid thin films and the effect of
nanostructures on the electrochromic characteristic of the films. They deposited WO
3
thin films at the substrate temperature of 400°C. The partial pressures of oxygen were
varied. Tungsten nanorods were prepared on FTO coated glass sheets by hydrother-
mal process. Optimized WO
3
layers were deposited on the TiO
2
nanorod film by
sputter deposition. They performed electrochemical, optical, and material analysis on
the films using CV, UV–visible spectrometry, x-ray diffraction (XRD), Raman, and x-
ray photoelectron spectroscopy (XPS). The enhanced CE of the optimized WO
3
films
was attributed to the big active surface area which favored H
+
ions intercalation in the
layers. The TiO
2
nanorods/WO
3
hybrid films showed a good electrochemical property
in terms of the diffusion coefficient of 1.8 10
7
cm
2
/s better than those of pure WO
3
(0.6 10
7
cm
2
/s) and TiO
2
nanorods (0.4 10
7
cm
2
/s).
Nah et al. [70] demonstrated that homogeneous and well-ordered arrays of
TiO
2
WO
3
nanotubes can be layered by anodization of Ti alloys in an ethylene
glycol/fluoride-based electrolyte under special electrochemical conditions. They grew
nanotube films on different substrates [Ti, Ti-0.2 at% W (Ti-0.2 W), and Ti-9 at% W
(Ti-9 W)] by anodization at 120 V in a solution of ethylene glycol with 0.2 Mol HF.
The growth time was controlled to achieve a comparable thickness of the layers.
Ordered oxide nanotube layers were obtained with a thickness of 1.1–1.2 μm and 85–
95 nm tube diameter. These aligned mixed oxide nanotube structures are very good
for enhanced electrochromic reactions. It was shown that only small amounts of WO
3
(such as 0.2 at %) can drastically improve the electrochromic properties (cycling
stability, contrast, onset potential) of nanotube layer-based devices, see Figure 2.
3.2 Ti
0.50
V
0.50
O
x
Burdis et al. [71] used RF sputtering from metallic targets for deposited thin films of
V
0.50
Ti
0.50
O
x
. They used this film as a potential counter electrode in investigating
5
Perspective Chapter: Electrochromic Efficiency in Ti
x
Me
(1-x)
O
y
Type Mixed…
DOI: http://dx.doi.org/10.5772/intechopen.1008197

electrochromic device behavior. They concluded that the film can reversibly store
relatively large amounts of charge and it is slightly yellow-looking in transmission, while
showing acceptably low electrochromic CE. The electrochemistry of V
0.50
Ti
0.50
O
x
is
found to be simple, in fact rather the same as that of WO
3
, for those reasons, they found
that this material was considered almost exemplary to use in such a variable transmis-
sion device. Charge capacities were measured to 60 mC/cm
2
for 300 nm film thickness.
The authors planned to characterize further the electrochromic coloration of these films
up to high levels of charge insertion and to determine the effect of repeated charging
and discharging on the lifetime of such films.
Marcel et al. [72] used the lamination of two tungsten and vanadium-titanium
oxide thin films to reduce the blue absorption of vanadium oxide prepared by roll-to-
roll radiofrequency sputtering technique. To produce flexible devices adaptable for
eyewear applications, an ITO-coated mylar substrate was used. The working electrode
has been set as Tungsten oxide, while the counter-electrodes that were examined
vanadium-titanium oxide mixtures. The electrolyte used to assemble both electrodes
was a polymer gel lithium ionic conductor constituted of a lithium bis(trifluoro-
methanesulfonyl)imide (LiTFSI, LiC2F6NO4S2) lithium salt dissolved in propylene
carbonate (PC) and incorporated within a photopolymerized acrylate matrix. They
investigated the electrochromic properties of the counter electrode at four different
atomic ratios of titanium in the (0–100%) range increased at 25% steps. A blue shift
effect in the transmittance spectra of as-deposited films was first observed as the
titanium amount was increased. In situ, optical behavior was investigated while the
potential range for cycling was (1.5-4 V), and the sample with equal proportion of
vanadium and titanium displayed a noteworthy neutrality of coloration. Complete
Figure 2.
(a) Cyclic voltammograms of the oxide nanotube (ONT) layers on Ti, Ti-0.2 W, and Ti-9 W performed between
0.7 and 1.0 V with a scan rate of 50 mV in 0.1 Mol HClO
4
electrolyte; (b) current density time curves
acquired by pulse potential measurement applied between 0.7 and 1.0 V with 30 s duration; (c) in situ
reflectance curves of Ti,Ti-0.2 W, and Ti-9 W ONTs obtained during potential pulsing applied between 1.0
and 0.7 V; and (d) optical images of the electrochromic effect of the different nanotube surfaces during
polarization cycling between 1 and 0.7 V. The inset of (b) shows integrated charge density (Q
d
) for the samples.
Reprinted (adapted) with permission from Ref. [70]. Copyright 2008 American Chemical Society.
6
Titanium Dioxide –Uses, Applications, and Advances

devices were prepared with different Ti/V ratios of 0, 1:3, 1:1, and 3:1 in the counter
electrode. The film thickness of tungsten oxide has been fixed to 300 nm, and the
thickness of vanadium-titanium oxide films has been set based on their respective
electrochemical capacity. The obtained electrochromic performances together with
their cycling lifetimes and response times were evaluated to find the optimal
vanadium-titanium composition.
3.3 TiO
2
: MoO
3
Shrestha et al. [73] fabricated self-organized TiO
2
–MoO
3
composite oxide
nanotubes with tunable characteristics by anodization of a Ti-Mo alloy and these
nanotube layers exhibited a considerably enhanced electrochromic color contrast
compared with simple TiO
2
nanotubes. They prepared self-organized binary oxide
nanotube layers: a single phase Ti-Mo (7 wt%) alloy sheet was polished to a mirror
finish, and it was used as a working electrode in a classical anodization assembly. This
consists of a traditional 3-electrode system with an Ag/AgCl (3 Mol KCl) reference
electrode and a Pt mesh as a counter electrode. The color contrast in terms of reflec-
tivity for the amorphous Ti-Mo-nanotubes is 2.5-fold higher than that of the amor-
phous TiO2-nanotubes for the same charge density.
Ezhilmaran and Bhat [74] prepared a bilayer electrode with nanoparticulate TiO2
in the bottom layer and randomly oriented MoO3 nanostructures as the top layer to
obtain electrochromic device. The TiO
2
, MoO
3,
and TiO
2
/MoO
3
films were prepared
using simple solution methods by spin-coating the precursor solutions on conducting
FTO substrates. After the spin-coating, the samples were dried and annealed. The
heterojunction film was prepared by spin-coating MoO
3
precursor solution on the
TiO
2
film. The electrode showed a superior behavior in terms of higher current
density and charge storage capacity as well as rate capability as compared to the
similar reports in the literature. A color contrast of 38%, switching response of 2s
and high CE of 72.5 cm2/C were obtained.
To enhance the CE, Ismaeel et al. [75] have performed electrochromic measure-
ments to the full composition range of reactive magnetron sputtered mixed Titanium
oxide and Molybdenum oxide (TiO
2
-MoO
3
). Spectroscopic ellipsometry (SE) has
been used to determine and map the composition and optical parameters. To check
the results of SE, scanning electron microscopy (SEM) with energy-dispersive x-ray
spectroscopy (EDS) has been used. Ti and Mo targets were put separately from each
other (see Figure 3a), and the indium-tin-oxide (iTO) covered glass sheets and Si-
probes on a glass holder (30 cm 30 cm) were moved under the two separated targets
(Ti and Mo) in a reactive argon-oxygen (Ar-O
2
) gas mixture, as it can be seen in
Figure 3. After one sputtering process, all the compositions (from o to 100) % have
been achieved by using this combinatorial process, in the same sputtering chamber.
Transmission electrochemical cell has been used to determine the CE (the change of
light transmission for the unit electric charge) for the mixed metal oxides (TiO
2
-
MoO
3
) that are deposited, see Figures 3 and 4. The two maximums in CE (see
Figure 4) can be explained by the fact that the Ti-rich side was at a much more higher
temperature during the deposition process, so the Ti-rich oxide is polycrystalline
while the Mo-rich side remains amorphous or nanocrystalline [75]. CE has been
considered an important parameter in this study. The maximum value of the CE is
22.2 cm
2
C
1
(at λ= 600 nm) at 60–40% Ti-Mo ratio on the Ti-rich polycrystalline
material, while CE is 19.8 cm
2
C
1
(at λ= 600 nm) at 20% - 80% Ti-Mo ratio on the
Mo-rich amorphous (or nanocrystalline) material.
7
Perspective Chapter: Electrochromic Efficiency in Ti
x
Me
(1-x)
O
y
Type Mixed…
DOI: http://dx.doi.org/10.5772/intechopen.1008197

Figure 3.
(a) Schematic of the two targets’arrangements in a closer position (35 cm from each other) and the chamber for
the DC magnetron sputtering device; (b) TiO
2
-MoO
3
layers on ITO-covered glasses after-electrochromic-
experiments. From Ref. [75].
Figure 4.
CE vs. Mo% for wavelengths from (400–800) nm of TiO
2
-MoO
3
. From Ref. [75].
8
Titanium Dioxide –Uses, Applications, and Advances

These results are concordant with the results of Habashyani et al. [76] which are
published in a recent paper. Using radio frequency magnetron sputtering (RFMS), the
authors have grown undoped and Ti-doped vertical nanowall structured MoS
2
thin
films and thermally oxidized these films to α-MoO
3
using the following deposition
parameters: 45 min oxidation at 380°C under 500 sccm of O
2
gas ambient. Sample
names’labeling was the following: undoped MoO
3
->MBO, Ti:MoO
3
with 20 W RF-
power - >MTO
20
, Ti:MoO
3
with 30 W RF-power - >MTO
30
, Ti:MoO
3
with 40 W RF-
power - >MTO
40
.
Ti has led to denser nanowall formations. Optical modulation (OM) in the visible
region was enhanced with increasing Ti concentration within the coloring potential
range of 0.2 to 0.45 V. This is relatively low working voltage, which makes the
signals energy efficient in electrochromic materials. The highest Ti-doped MoO
3
(MTO
40
) and undoped (MTO) samples showed 52.2% and 37.6% OM at λ= 700 nm
(47.8% and 25.7%, respectively, at λ= 550 nm) under 0.45 V applied potential. On
the other hand, the coloring times for MBO, MTO
20
, MTO
30
, and MTO
40
were 4.7,
4.1, 6.2, and 2.9 s, respectively, while the bleaching durations were 3.1, 1.4, 1.1, and
1.2 s for samples. MBO sample is the undoped while the Mo/Ti ratio in sample MTO
20
is 79.5, in MTO
30
is 17.0, in MTO
40
is 6.7 (highest Ti-doped).
Although the nanowall structure of the highest Ti-doped thin film (MTO
40
) was
destroyed, this thin film showed the best coloring response time and OM at the visible
wavelengths. MTO
20
and MTO
30
samples, on the other hand, have performed better
at longer wavelengths with higher OM and CE. As a result, Ti-doping has a beneficial
effect on the electrochromic behavior such as OM, CE, and response times during
coloring and bleaching of the MoO
3
. These Ti-doped MoO
3
electrochemical charac-
teristics demonstrate the suitability of these materials for device applications.
3.4 TiO
2
: SnO
2
Ismaeel et al. [77] determined the optimal composition of reactive magnetron-
sputtered combinatorial mixed layers of titanium oxide and tin oxide (TiO
2
-SnO
2
) for
electrochromic purposes. SE was used to obtain the thickness and composition maps
of the sample. They also compared the performance of different optical models, such
as 2-Tauc–Lorentz multiple oscillator model (2 T–L) or the Bruggeman effective
medium approximation (BEMA) to map the sample parameters. To check the results
of SE, SEM, with EDS was used. It was shown that in the case of molecular-level
mixed layers, 2 T–L is better than an EMA-based optical model. By using SE, the
Figure 5.
(a) The imaginary part of the refractive index (k Amplitude) as a function of time for highly conductive Si in the
liquid cell during coloration (time-scan, simple 2-layer Cauchy model). From 0 to 4 min, there is low absorption,
however, from 4 to 8 min, there is a growing absorption; and (b) Map of the k parameter after coloration (simple
1-layer Cauchy model). From Ref. [77].
9
Perspective Chapter: Electrochromic Efficiency in Ti
x
Me
(1-x)
O
y
Type Mixed…
DOI: http://dx.doi.org/10.5772/intechopen.1008197

electrochromic efficiencies of mixed metal oxides (TiO
2
-SnO
2
) deposited by reactive
sputtering were also mapped, too, see Figure 5.
The coloration process was followed in situ by SE at the center point of the mixed
metal oxide –highly conductive Si sample. They could map the colorized layer using a
simple one-layer Cauchy dispersion optical model after the coloration process. For
the Cauchy model, the k Amplitude (extinction) parameter has been considered a
good indicator of the CE, as it is shown in Figure 5b. The maximum k value exhibits
that the optimal composition is at (30%) TiO
2
–(70%) SnO
2
. See Table 1.
4. Conclusions
Many binary oxides were studied as potentially promising EC materials. However,
most of the studies have investigated only a few compositions. Some of them studied
only the role of adding a single percentage of a secondary material, emphasis of
research was put on studying the effects of doping. Only a few examples can be found
where a comprehensive investigation spanning the full compositional range between
the component oxides was made. Note, that in most cases the mixed metal oxides
showed better EC properties than the pure oxides. For example, Ismaeel et al. [75]
found a fourfold enhancement of CE in Titanium-Molybdenum oxide mixed films.
Therefore, in order to enhance the EC performance of materials further focus should
be put on studying properties of mixed oxide materials in the full (0–100%) compo-
sition range. Combinatorial sputtering techniques offer a feasible way to prepare
samples for this purpose.
Acknowledgements
This work has been funded by NKFIH OTKA K 143216 and 146181 projects. Project
TKP2021-EGA-04 acknowledges the support from the Ministry of Innovation and
Technology of Hungary financed under the TKP2021 funding scheme. The work with
X(cm) k Amplitude (Error 0.005)
3.5 0.0002
3 0.0025
2.5 0.044
2 0.004
1.5 0.015
1 0.025
0.5 0.056
0 0.041
0.5 0.092
1 0.105
1.5 0.075
Table 1.
k Amplitude vs. Position at the center line after the colorization in the dry state. From Ref. [77].
10
Titanium Dioxide –Uses, Applications, and Advances

20FUN02 “POLight”project has received funding from the EMPIR program, from the
European Union’s Horizon 2020 research and innovation program. Noor Taha Ismaeel
acknowledges the Stipendium Hungaricum scholarship.
Author details
Zoltán Lábadi
1
, Noor Taha Ismaeel
2,3
, Peter Petrik
1,4
and Miklós Fried
1,5
*
1 Institute of Technical Physics and Materials Science, Centre for Energy Research,
Budapest, Hungary
2 Doctoral School on Materials Sciences and Technologies, Óbuda University,
Budapest, Hungary
3 Institute of Laser for Postgraduate Studies, University of Baghdad, Baghdad, Iraq
4 Faculty of Science and Technology, Department of Electrical Engineering, Institute
of Physics, University of Debrecen, Debrecen, Hungary
5 Institute of Microelectronics and Technology, Óbuda University, Budapest, Hungary
*Address all correspondence to: fried.miklos@uni-obuda.hu
© 2024 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of
the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0),
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11
Perspective Chapter: Electrochromic Efficiency in Ti
x
Me
(1-x)
O
y
Type Mixed…
DOI: http://dx.doi.org/10.5772/intechopen.1008197

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Perspective Chapter: Electrochromic Efficiency in Ti
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DOI: http://dx.doi.org/10.5772/intechopen.1008197