Photonic crystals in biology

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Poster Session, Tuesday, June 15
Theme A1 - B702
Structural and Electrical Properties of Ru Doped ZnO Film Fabricated by Sol-Gel Technique and
using for Gas Sensing
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UMurat BektasUP P*, M.ErolP P, O. SancakogluP P, M. F. EbeoglugilP H. SözbilenP
3P, Ömer Mermer 2,3
1,2
P, and Erdal CelikP
1
PDokuz Eylul University, Department of Metallurgical and Materials Engineering, Tınaztepe 35160 Izmir-TURKEY.
PDokuz Eylul University, Center for Fabrication and Application of Electronic Materials (EMUM), Tınaztepe 35160 Izmir-TURKEY.
3
PEge University, Deparment of Electrical and Electronic Engineerings, Bornova, 35100 Izmir-Turkey
2
Abstract-In this study, ZnOR Rthin films were deposited on glass substrates via sol-gel technique for sensor applications. Transparent solutions
were prepared from Zn and Ru based precursors. The solutions were deposited on glass substrates by using spin coating technique which
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provides thin and smooth films. Deposited films were dried at 300 P PC for 10 min in order to remove hydrous and volatile content,
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subsequently to remove organic content films were heat treated at 500P
PC for 5 min and then they were annealed at 600P PC for 1 hour to
obtain ZnO based films in air atmosphere. Finally the surface morphology and roughness of the films were determined via AFM (atomic
force microscopy) and profilometer respectively. The phase structure was determined by XRD. The electrical conductivity of the film
dependence of temperature was measured to identify the dominant conductivity mechanism. The optical parameters of the film were also
determined by using spectrophotometer.
The importance of zinc oxide (ZnO), among other metal
oxides, is increasing due to many applications. Thin films
of zinc oxide combine interesting properties such as nontoxicity,
good electrical properties, high luminous
transmittance, excellent substrate adherence, hardness,
optical and piezoelectric behaviour and its low price. ZnO
has relatively high physical and chemical stabilities, and
hence it has many high temperature applications [1].
Zinc oxide (ZnO) is an important multifunctional
material with applications such as transistors, gas sensors,
solar cells, nanocantilevers, etc [2]. Sensors for toxic gases
have attracted much attention due to the growing concern
of environmental protection and safety. The major
applications of gas sensors are domestic or industrial
security, environmental and emission monitoring,medical
and agribusiness controls, etc. [3]. Although efforts are
continuing for CO gas sensing using the hetero structure of
SnO2 and ZnO [3], experimental results on pure ZnO for
CO sensing is lacking and it may be related to rapid grain
growth and densification. For gas sensors, it is necessary
to have a porous microstructure with small particle size
yielding large ratio of the surface area to the bulk [4].
Undoped ZnO responses perceptibly to LPG while Ru
doped sample highly senses ethanol vapors [5]. Scientific
studies about this topic point out that substitution causes
change in the electrical properties and particle size. Also
substitution is important in selective sensing of gases or
substances.
In this research; pure, Ru substituted ZnOR Rthin film were
deposited on glass substrates. A sol-gel route was derived
to produce thin films.
The sol–gel spin coating method has distinct advantages
such as cost effectiveness, thin, transparent,
multicomponent oxide layers of many compositions on
various substrates, simplicity, excellent compositional
control, homogeneity and lower crystallization
temperature [6].
Surface morphology of Ru-ZnO thin film obtained by
Atomic Force Microscopy (AFM) and illustrated in
Figure1. Spin coating technique provides nanoscale and
smooth films to be deposited. Thus the films were
deposited by technique mentioned above nano scale pores
and nano Scale Island like structures can be obtained. The
decrease in the pore size of a sensor from micron scale to
nano scale provides high efficiency and selectivity about
gas or substance sensing.
Figure 1. Surface morphology of Ru-ZnO thin film obtained by
Atomic Force Microscopy (AFM) technique
Electrical parameters of pure ZnO and Ru doped ZnO
films will be determined by using conductivity
measurement. Optical transmittance and reflectance
spectra will also be measured in the wavelength range of
325–800 nm by using V-530 JASCO UV/VIS
Spectrophotometer. Based on these data, optical
parameters are calculated according to well-known
formulas [6]. Finally using of resistance and capacitance
measurement techniques will be used for the
characterization of the gas sensing properties (such as
sensitivity, selectivity, and time responses).
The authors are indebted to State Planning Foundation
(DPT) and Dokuz Eylul University for financial support.
*Corresponding author: HTmurat_bektas3585@hotmail.comT
[1] T. Ivanova, A. Harizanova, T. Koutzarova, B. Vertruyen, ,
Materials Letters, in press, 2010
[2] M. Yang, D. Wang, L. Peng, Q. Zhao, Y. Lin, X. Wei,
Sensors and Actuators B 117 (2006) 80–85
[3] E. Celik, U. Aybarc, M. F. Ebeoglugil, I. Birlik, O. Culha, , J
Sol-Gel Sci Technol (2009) 50:337–347
[4] H.-W. Ryu, B.-S. Park, S. A. Akbar, W.-S. Lee, K.-J.
Hong,Y.-J. Seo, D.-C. Shin, J.-S. Park, G.-P. Choi, Sensors and
Actuators B 96 (2003) 717–722
[5] S. C. Navale , V. Ravi, I.S. Mulla, Sensors and Actuators B
139 (2009) 466–470
[6] M. Caglar, et.al., Applied Surface Science 255 (2009) 4491–
4496
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