Third Day Poster Session, 17 June 2010 - NanoTR-VI

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Poster Session, Thursday, June 17
Theme F686 - N1123
Electrical and Optical Properties of Al Doped ZnO Film and Potential Applications of Gas Sensors
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UO. SancakogluUP
P*, M. ErolP
P, M. BektasP
P, F. EbeoglugilP
P, H. SozbilenP
3P, O. Mermer 2,3P, E. Celik 1,2
1
PDokuz Eylul University, Department of Metallurgical and Materials Engineering, Tinaztepe Campus, 35160 Buca, Izmir-Turkey.
2
PDokuz Eylul University, Center for Fabrication and Application of Electronic Materials (EMUM), Tinaztepe Campus, 35160
Buca, Izmir-Turkey
3
PEge University, Deparment of Electrical and Electronics Engineering, 35100, Bornova, Izmir-Turkey.
Abstract-Undoped and Al doped semiconductor ZnO films on Si(100) and glass substrates were prepared by sol-gel technique. For this
propose, transparent solutions were prepared with Zn and Al based precursors. The solutions were deposited on glass substrates using spin
coating technique which decreases the film thickness up to nanoscale and gives the coating a smooth characteristic. Deposited films were dried
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at 300P PC for 10 min in order to remove hydrous and volatile content, subsequently films were heat treated at 500P PC for 5 min. to remove
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organic contents and then to obtain ZnO phase structure the films were annealed at 600P PC for 1 hour in air atmosphere. Finally the surface
morphologies and roughness values of the films were determined via AFM (atomic force microscopy) and profilometer, respectively. The
structural and optical properties of these films have been investigated by XRD (x-ray diffractometer) and optical properties such as
transmittance spectrum, optical band gap, and optical constants (refractive index, extinction coefficient, real and imaginary parts of the dielectric
constant) of the films were determined.
Zinc oxide (ZnO) has attracted extensive interest because
of its important role in various applications, for example, gas
sensor [1], varistors [2], surface acoustic wave devices [3],
optical waveguides [4] as well as blue/UV light emitting
devices [5]. In addition, ZnO has been considered as an
excellent candidate to replace indium tin oxide (ITO) and tin
oxide (SnO2) as transparent conductive electrodes in flat panel
display and solar cell devices [6,7]. The advantages of zinc
oxide include inexpensiveness and relative ease of
lithography. However, the electrical conductivity of un-doped
zinc oxide is not high enough for practical application. Further
reduction of resistivity of zinc oxide can be achieved either by
doping group III elements such as B, Al, In and Ga to replace
zinc atoms [8] or group IV elements, F, to substitute oxygen
atoms [9].
The structural and morphological properties of
semiconductor oxides have a substantial effect on their optical,
electrical and gas sensing properties. The controlledparticle
size and morphology facilitate the desired characteristics in
the materials. Several simplewet chemical routes like sol–gel,
co-precipitation and Pechini route have been adapted to form
nanostructures [10].
specific acid-alcohol medium to remove the contaminations
and prepare the surface for sol-gel coating. The films were
deposited by the technique detailed in Figure 1.
Figure 2 shows the x-ray diffraction spectra of the pure
ZnO film. It also represents the success of the coating process.
Figure 2. X-ray diffraction spectra of the pure ZnO film.
The structural and optical properties of the films will be
shown in details. b)
The authors are indebted to State Planning Foundation
(DPT) and Dokuz Eylul University for financial support.
*Corresponding author: orkut.sancakoglu@deu.edu.tr
Figure 1. Flow chart of sol-gel processing for ZnO thin films.
In the present study; pure, and Al substituted ZnOR Rthin films
were deposited on glass substrates by sol-gel method and spin
coating technique. Si(100) and glass substrates were
mechanically cleaned by using a new designed apparatus in a
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