International Journal of Application or Innovation in Engineering & Management (IJAIEM)
Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com
Volume 2, Issue 10, October 2013
ISSN 2319 - 4847
Structural properties of borondoped zinc oxide
nanostructure films depositon Glass Substrate
Rashid HashimJabbar1, Abdulhussein K. Elttayef1,Ashwaq A. Jabor1, Abdulkareem H. Hashim2
1
Center of Applied Physics, 2Center of advance materials,Ministry of Science and Technology, Baghdad, Iraq
Abstract
This paper presents the structural properties of boron doped ZnO nanostructuresZnO:Bdeposited at 450 o C on glass substrates by
chemical spray pyrolysis in thichness(150±5 nm). The structure of ZnO:Bnanostructure films hasbeen found to exhibit the
hexagonal wurtzite structure. The increase of Boron concentration caused to decrease the grain size.interplaner spacing in the
ZnO:B(4%) be in the maximum value for(100) plane and the minimum value for (002 and 101) planes. The structural details and
microstructurewere obtained from X-ray diffraction.
Keywords:ZnOnanostructures, boron doped, structural properties.
1. Introduction
Semiconductor ZnO has been the subject of research for many applications forthe past several years, because the material
is nontoxic, biosafe, chemically stable, and biocompatible. ZnO has a direct wide bandgap of around 3.2-3.37eV at room
temperature 300K[1,2,], where the bottom of the conduction band is formed from the 4s levels of Zn2+ and the top of the
valence band is built from the 2p orbitals of O2-. It has strong ionic bonding and exciton binding energy of 60 meV [3].
low resistivity and high transparency in the visible range and high light trapping characteristics [3]. [4]ZnO has attracted
increasing attention as a potential material for optoelectronic devices such as low threshold blue/UV lasers, solar cells,
LEDs, sensors, display devices and photodetectors[5-7].The synthesis of nanoparticleshas become a highly developed _eld
owing to thescienti_c and technological interest due to the structuralpeculiarities and unusual physical and chemical
propertiesthey may lead to [4]. In recent years, it has beenfound that ZnO can be synthesized by various routessuch as
electron beam evaporation technique [5], chemicalspray pyrolysis technique [1], RF thermal plasmaevaporation [6],
sol_gel method [3, 7], and precipitation[1, 7] methods. Among these methods, precipitation hasmany advantages over the
other methods, for example,it is unsophisticated and a low cost method[4,8,2].Zinc oxide (ZnO) has been used in a wide
range of products for many years, including, amongothers, varistors, surface acoustic wave devices and cosmetics. Besides
these established applications,ZnO and its ternary alloys are now also being considered as potential materials
foroptoelectronic applications, such as light emitting diodes, photovoltaics, sensors, displays, etc[9].
2. Experimental:
Nanostructure films of ZnO,ZnO:Bprepared by spray pyrolysis deposition (SPD) technique in air from zinc nitrate
(Zn(NO3)2.6H2O), and boric acid (H3BO3) diluted with distilled water to concentration of molarities equal 0.075 M,
(Zn(NO3)2.6H2O) is a solid material which has a white color and its molecular weight (297.4 g/mole). The deposition
method involves the decomposition of an aqueous solution of zinc nitrate. The spray solution is sprayed onto heated
substrates held at 450oC. The time of the deposition is 3 sec. each 42 sec., Compressed air is used as a gas carrier and it is
fed with the solution into a spray nozzle at a preadjusted constant atomization pressure. Film thickness(t=150±5 nm) was
determined by(TFProbeTM Spectroscopic Reflectometer film thickness measurement system). Diffraction studies are
carried out using X- Ray Shemadz XRD – Diffractrometer (operated at 40 kV an accelerating potential and 30 mA with
filtered CuKα radiation 0.15406 nm wavelengths) was performed to identify the crystalline phases present in the
deposited films.
3. Result and discussion:
3.1. Structural analysis:
The XRD graphs of ZnO:Bnanostructure films are shown in fig.1. It is obvious the nanostructurefilm is polycrystalline
and all the samples have hexagonal wurtzite structure. the intensity of ZnO pure nanostructure film is more than the
intensity of ZnO:Bnanostructure for (002) plane.
ZnO:B 8%
Intensity(a. u.)
ZnO:B 6%
ZnO:B 4%
ZnO:B 2%
ZnO pure
20
25
30
35
40
45
50
55
60
2θ(deg.)
Figure 1. X-ray diffraction pattern ofZnO:B nanostructure with concentration: 0.0 to 8 at.%.
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Volume 2, Issue 10, October 2013
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The values which measured by XRD instrument of diffraction angle(2θ), Interplaner spacing(d) and Full Width at Half
Maximum (FWHM) are in table(1).
Table 1: XRD patterns, inter-planar spacing and angular full width at half maximum for ZnO:Bnanostructure films
deposited atsubstrate temperature 450 o C on glass substrates.
h
Doping(
2θ(de
d(n
FWHM(de
kl
%)
g.)
m)
g.)
The Average grain size
1
00
1
00
1
00
1
00
1
00
0
-
-
-
2
31.808
0.28
111
0.57
4
31.716
0.28
190
0.45
6
31.829
0.28
093
0.58
8
31.785
0.28
130
0.91
0
02
0
02
0
02
0
02
0
02
0
34.475
0.25
994
0.40
2
34.577
0.25
920
0.48
4
34.659
0.25
861
0.67
6
34.621
0.25
888
0.69
8
34.557
0.25
935
0.81
1
01
1
01
1
01
1
01
1
01
0
36.246
0.24
764
0.39
2
36.281
0.24
741
0.51
4
36.410
0.24
656
0.59
6
36.375
0.24
679
0.66
8
36.317
0.24
717
0.86
was calculated by Scherer equation [10]:
…….. (1)
Where
=0.94 called(Scherer'sconstant), λ is the wave length of incident X-ray radiation , β is the intrinsic full
width at Half Maximum of the peak , and θ is the Bragg's diffraction angle of the respective XRD peak .Assumes the
world Warren that the mathematical representation of curves resulting from the X-ray diffraction (XRD)depends
primarily on the amount of similarity between these curves and functions of each of the Cauchy and Gauss, inthe case
considered curve X-ray diffraction is similar to function Cauchy and take the form of
, thecorrection is given by
the following relationship, which was called (Scherer's correction):
Where
(
is the measured full width at Half Maximum of the peak, is the instrumental broadening[11],where
for the used instrument.Compensation equation (2) in the relationship (1) we get:
)
In the case considered X-ray diffraction curve similar to the function Gauss which takes the form (
) theaccuracy to
be higher because of the great similarity between this function and the diffraction curves; it was suggested(Warren
correction) form:
This correction called (Warren's Correction). Compensation equation (4) in the relationship (1) we get:
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Since the output line shape does not resemble the Gauss curve and Cauchy curve completely, so these relations
havelimited operation values. If the intensity curve does not sharp may be used (Scherer's correction) or
(Warren'sCorrection) former because the difference between the values given by relations (3) and (5) is not large, which
meansthat the decrease of the curve breadth (an increase of sharpness) means that the effect of the amount ( ) is
significant,since the width of the curve in the half intensity (FWHM) is inversely proportional with grain size according
toequation (1), the decrease in (FWHM) leads to increase in the grain size, which means that few crystal defects
arepresent in the sample.Moreover, Warren was suggested a relationship takes into account the geometric meaning which
is [12, 13]:
Compensation equation (6) in the relationship (1) we get:
The grain size of (100),(002) and (101) planes using equations (1,3,5 and 7) is in the table(2).
Table 2: The grain size for 100, 002 & 101 plane of ZnO:Bnanostructure films.
hk
ℓ
Doping(%
)
eq.(1)
eq.(3)
Grain size(nm)
eq.(5)
eq.(7)
10
0
10
0
10
0
10
0
10
0
0
2
4
6
15.2
19.2
15.0
18.9
25.4
18.6
15.5
19.8
15.3
17.1
22.4
16.9
8
9.5
10.8
9.5
10.1
00
2
00
2
00
2
00
2
00
2
0
21.9
30.4
22.8
26.3
2
4
6
18.0
12.9
12.7
23.3
15.4
15.1
18.5
13.1
12.9
20.8
14.2
13.9
8
10.8
12.5
10.9
11.6
10
1
10
1
10
1
10
1
10
1
0
2
4
6
22.2
17.0
14.9
13.2
10.1
30.8
21.7
18.3
15.8
11.6
23.1
17.5
15.2
13.4
10.2
26.7
19.5
16.7
14.5
10.9
8
Fig.2. showes the difference among the equations 1,3,5 and 7 to the plane 002, where the median value represent the
geometric meaning of Warren correction i.e.(eq.7).
35.0
002
Grain size(nm)
30.0
25.0
eq. 1
eq. 5
20.0
eq. 3
eq. 7
15.0
10.0
0
2
4
Doping(%)
6
8
10
Fig.2. grain size of 002 plane calculated by Scherer and Warren and their corrections
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The dislocation density
which represents the defect in the film was determined from the formula[16]:
Using eq.(7) and eq.(8), the grain size anddislocation densityfor (101, 002 and100) plane are shown in figure(3).
100
002
a
101
Grain size(nm)
25.0
20.0
15.0
10.0
5.0
0.0
0
1
2
3
4
5
6
7
8
9
Dislocation density(1011 lines/cm2)
30.0
10
100
9
002
b
101
8
7
6
5
4
3
2
1
0
0
1
2
3
Doping(%)
4
5
6
7
8
9
Doping(%)
Figure 3.(a)grain size, (b) dislocation density ofZnO:Bnanostructure with concentration: 0.0 to 8 at.%. for (100,002 and
101) planes.
The lattice parameters a and c were calculated from the XRD pattern using the equation[14,15].
………(9)
The microstrain ( ) can be calculated from the relation[16]:
Fig.(4) shows the micro strain of ZnO: nanostructure films Using eq.(9) and (10).
7
Micro strain(X10-3)
6
5
4
3
2
1
100
0
0
2
4
002
101
6
Doping(%)
8
10
Fig.4.microstrain of ZnO:B nanostructure thin films with concentration: 0.0 to 8 at.%. for (100,002 and 101) planes.
XRD measurements of the interplaner spacing(d)for(100,002 and 101) planes as shown in fig.(5) where in the
ZnO:B(4%) the maximum value of (d) for(100) plane and the minimum value for (002 and 101) planes.
0.2602
0.2816
0.2814
0.2812
0.281
0.2808
0.2806
0.2804
0.2478
002
0.26
0.2598
0.2596
0.2594
Interplanerspacing(nm)
100
Interplaner spacing(nm)
Interplaner spacing(nm)
0.282
0.2818
0.2592
0.259
0.2588
0.2586
0
2
4
6
8
Doping(%)
10
0.2474
0.2472
0.247
0.2468
0.2466
0.2464
0.2584
0.2802
101
0.2476
0
2
4
Doping(%)
6
8
10
0
2
4
6
8
10
Doping(%)
Fig.5.Interplaner spacing of ZnO:B nanostructure thin films with concentration: 0.0 to 8 at.%. for (100,002
and 101) planes.
3.3. Surface morphology
The surface morphology of the ZnO:B nanostructures is observed using scanning electron microscope (SEM)as shown in
figure(6). The change in the morphology of ZnO:B nanostructure films is due to the difference in ionic radius between
B3+ (0.041 nm) with Zn2+ (0.074 nm)[17].The pictures of morphological structure of ZnO:B nanostructure films were
obtained by using an atomic force microscopy are shown in Figure(7).
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0.0
2%
4%
6%
8%
Figure.6.SEM image of ZnO:B nanostructure with concentration: 0.0 to 8 at.%.
a
b
c
d
e
Figure 7. Morphological of the ZnO:B nanostructures with concentration: (a) 0%, (b) 2%, (c) 6%, (d) 8% by
using an atomic force microscopy (AFM).
4. Conclusions
ZnO:Bnanostructures of different shapes have been synthesized on glass substrate using a low cost spray pyrolysis
deposition. It wasfound that the increase of concentration of B due to decrease of grain size in generaland varying the
morphology, (002 and 101) plane has the minimum valueof interplaner spacing in the ZnO:B(4%).
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Volume 2, Issue 10, October 2013
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AUTHOR
Rashid HashimJabbar, Ph.D student. Presently, M.Sc. in Physics Science degree in 2009, Al-Mustansiriyah
University, College of Science, Dept. of Physics, and BSc. in Department of Physics College of science in
1989, from University of Baghdad, a researcher at the Applied Physics Center and member of thin films
application Department, Ministry of Science and Technology, Baghdad, Iraq.
AbdulhusseinK.Elttayef is currently a professor of physics At the Applied physics center, Baghdad, Iraq. He
received his Ph.D Degree from Heriot –Watt University (U.K) in 1990. His currently research Interests include
the preparation of nano films (semiconductors and polymers) by different methods for applications of gas
sensors, solar cells and optical detectors. He has written 40 scientific publications in this area.
Ashwaq Abdul Husseinjabor, , M.Sc.in physical Chemistry Department
of Science ,University of
Baghdad,2003. B.Sc.chemistry collage of science University of Baghdad 1990, , a researcher at the Applied
Physics Center and member of thin filmsapplication Department, Ministry of Science and Technology,
Baghdad, Iraq.
Abdulkareem H. Hashim , professional of X-ray Diffraction for ten years, Center of advance materials,
Ministry of Science and Technology, Baghdad, Iraq.
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