by ackapop katesomboon department of physics faculty of science king mongkut's university of...
TRANSCRIPT
SURFACE MODIFICATION OF F-DOPED TIN OXIDE THIN FILMS BY WET CHEMICAL ETCHING
ByAckapop Katesomboon
Department of Physics Faculty of Science King Mongkut's University of Technology
Thonburi
Introduction
Glass
TCO
amorphous silicon
metal
LIGHT
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Figure 1. Structure of amorphous silicon solar cell
Introduction (Cont.)
SnCl4(l)+2H2O(l)
SnO2 (S)+4HCl(l)
SnCl4(l)+2H2O(l)
SnO2 (S)+4HCl(l)
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The chemical reaction of SnO2 films coating is
Reverse reaction is
SnO2
Glass
SnO2
SnCl4+2H2OSnO2+4HCl
UV-Vis Spectrophotometer
Atomic Force MicroscopeFour Point
Probes 5
Experiment
Percent transmissio
nrms roughness
Sheet resistance
Experiment (Cont.)
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Effect of etching concentration / etching time
Effect of etching temperature / etching time
Table 1: Preparation conditions of etching time and HCl concentration at room temperature.Concentration
(%)
Etching time (min)
1, 3, 5 1, 5, 10, 15
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Experiment(Cont.)
Results and Discussion
0 2 4 6 8 10 12 14 1660
62
64
66
68
70
Tra
nspa
rent
(%
)
Etching time (min)
non etching HCl 1% HCl 3% HCl 5%
Fig. 2. The relationship between the percent transmission and the etching times of the specimens etched at different concentration.
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Optical propertie
s
Morphological properties
Results and Discussion
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HCl 1% 1min
Non etching
Fig 3. 3-D images of spacimensHCl 5% 15min
Etching time
(min)
Con.
(%)
Roughness rms (nm)
Roughness max (nm)
Surfacearea(µm2)
non etched 32.40 225.24 107.021 1 44.20 387.00 121.795 15 40.58 339.95 125.13
Table 2: The roughness of specimen form AFM of relationship between etching concentration and etching time.
Morphological properties
Results and Discussion
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0 2 4 67.5
8.0
8.5
9.0
9.5
10.0
Sh
eet
resi
stan
ce(
/sq)
concentration (%)
non etching 1min 5min 10min 15min
Electrical properties
Fig. 4. The relationship between the sheet resistance and the concentration of the specimens etched at different of HCl etching times from 1-15 min.
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Results and Discussion
Temperature(oC)
Etching time (min)
40, 45, 50 1, 8, 15
Table 3: Preparation condition to investigate the effect of temperature and etching time at 1% HCl concentration.
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Experiment (Cont.)
Optical properties
34 36 38 40 42 44 46 48 5060
62
64
66
68
70
Tra
nspa
rent
(%
)
Temparature (oC)
non etching 1 min 8 min15 min
Fig. 5. The relationship between the percent transmission and the temperature of the specimens etched at different etching times.
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Results and Discussion
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Non etching
50oC 15 min
40oC 1 min
Morphological properties
Fig. 6. 3-D images of spacimen
Results and Discussion
T
(oC)
Etching time(min)
Roughness rms (nm)
Roughness max (nm)
Surfacearea(µm2)
non etched 32.40 225.24 107.0240 1 44.49 346.28 128.2850 15 44.92 390.89 130.96
Table 4: The roughness of specimen form AFM of relationship between temperature and etching time.
Morphological properties
Results and Discussion
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38 40 42 44 46 48 507.5
8.0
8.5
9.0
9.5
10.0
Shee
t re
sist
ance
(/s
q)
Temparature (oC)
non etching 1 min 8 min15 min
Fig. 7. The relationship between the sheet resistance and the temperature of the specimens etched at different of etching times from 1-15 min.
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Electrical properties
Results and Discussion
Conclusion
• In the low concentration of etching concentration from 1-5%, the percent transmission, sheet resistance and morphology varied in a small region when changing etching time.• The etching temperature was
not important parameter of this experiment.
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References
[1] N. Senoussaoui, T. Repmann, T. Brammer, H. Stiebig, H. Wangner, Rev. Energ. Ren. 3 (2000) 49-56. [2] N. Amin, T. Isaka, A. Yamada, M. Konagai, Solar Energy Materials & Solar Cells. 67 (2001) 195-201. [3] A. Krasnov, Solar Energy Materials & Solar Cells. 94 (2010) 1648-1657. [4] J. Muller, B. Rech, J. Spinger,M. Vanecek, Solar Energy, 77 (2004) 917-930.[5] A. Fuchs, H- J. Schimper, A. Klein, W. Jaegermann, Energy Procedia, 10 (2011) 149-154.[6]A. Katesomboon,S. Dumrongrattana, T. Lachit, T. Jutarosaga, W. Onreabroy, Physical Propertes of Etching F-Doped Tin Oxide Film for Photovoltaic Application, 38th Congress on Science and Technology of Thailand, Chiangmai, Thailand, (2012), p 162.
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