Photonic crystals in biology

P Torr.
pressure
P
pressure
P and
P
pressure.
Poster Session, Tuesday, June 15
Theme A1 - B702
Characteristics of TiOR2R Thin Films Produced by Using the Pulsed Laser Deposition Method
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UMesure Mutlu SanliUP P*, Erhan AkmanP P, Elif KacarP P, Arif DemirP
1
PUniversity of Kocaeli, Laser Technologies Research and Application Centre, 41380 Umuttepe, Kocaeli
Abstract- In this study, TiOR2R (titania) thin films were obtained using the third harmonic (355 nm) of pulsed Nd:YAG laser. Optical
characteristics of the thin films deposited on microscopic glass slides were investigated as deposition time (film thickness), OR2R
Deposition process carried out at vacuum ambient with oxygen existence and at room temperature. Microscopic, spectroscopic and ellipsometric
investigations were done to get the optical properties.
TiOR2 R(titania) is a material that has been studied many times
because of its excellent properties. Hardness, high chemical
stability, high physical resistance, high refractive indices make
it requested material for many applications. The transparency
feasibility from UV to IR region makes it important for optical
coating applications. There are many different studies made by
TiOR2R as a functional material, electrochromic, photocatalytic
[1-2], solar cells, and gas sensors. Deposition of thin films for
various applications by using pulsed laser deposition method
gives opportunity to control and form desired film structure.
Detailed studies were described in literature [3, 4]. The
technological developments have provided significant
improvements in this method. The recent studies [5] indicate
that if the ambient OR2R and post annealing temperature
increased the anatase phase turn into rutile phase.
In this study TiOR2R thin films have been obtained using the
third harmonic (355 nm) of pulsed Nd:YAG laser, frequency was
-3
10Hz. Thin films have been grown on glass slides at 9x10P
-1
Torr vacuum then the OR2R was applied at 5x10P
0
5x10P Target material is Ti metal which is rotated 16
rpm (revolutions per minute) to avoid of drilling. Ablation
processes were continued during 30 min and 45 min. Laser
beam was focused using 150mm lens.
The thicknesses of the obtained TiOR2R thin films were
measured by ellipsometre. The absorption coefficient, , of the
deposited thin film was determined by [6]:
Transmittance (%)
100
90
80
70
60
50
40
30
20
10
0
ln(1/ T )
(1)
d
250 450 650 850
lambda (nm)
1/2
h C h
E gap
( )
(2)
2
The plot of (h)P P-h is given in Figure 2. From the
intersection of the photon energy axis gives the band gap of
the titania film.
(abs*photon energy)1/2
0,0018
0,0016
0,0014
0,0012
0,001
0,0008
0,0006
0,0004
0,0002
0
0 0,5 1 1,5 2 2,5 3 3,5 4 4,5
Photon Energy (eV)
Figure 2. Optical Transmittance spectra of TiOR2R thin film on glass
slide.
*Corresponding author: mesuremutlu@kocaeli.edu.tr
[1] S.C. Jung, S.J. Kim, N. Imaishi, Y.I. Chod, Applied Catalysis B:
Environmental 55 (2005) 253–257.
[2] B.S. Richards, J.E. Cotter, C.B. Honsberg, Appl. Phys. Lett. 80
(2002) 1123–1125.
[3] D.B.Chrisey, G.K.Hubler (ed), John Wiley & Sons Inc. 1994
[4] R.Eason (ed), John Wiley & Sons Inc. 2007
[5] G. Shukla, P. K. Mishra, A. Khare, Journal of Alloys and
Compounds 489 (2010) 246–251
[6] Aarik J, Aidla A, Kiisller A A, Uustare T and Sammelselg V
1997 Thin Solid Films 305 270
[7] Tauc J and Menth A 1972 J. Non-Cryst. Solids 8–9 569
Figure 1. Optical Transmittance spectra of TiOR2R thin film on glass
slide.
Film thickness, d, and the transmittance spectra, T, was
derived to calculate the absorption coefficient, . The optical
energy band gap, ERgapR, for the TiOR2R films on glass was
determined from the transmission spectra (Figure 1) using
Tauc relation [7].
6th Nanoscience and Nanotechnology Conference, zmir, 2010 408