1. By Ackapop Katesomboon Department of Physics Faculty of Science King Mongkut's University of Technology Thonburi

2. Conclusion 2 Introductio n Experiment Results and Discussion

3. Introduct ion Glas s TCO amorphous silicon metal LIGHT 3 Figure 1. Structure of amorphous silicon solar cell

4. Introduction (Cont.) SnCl 4 (l)+2H 2 O(l) SnO 2 (S)+4HCl(l) SnCl 4 (l)+2H 2 O(l) SnO 2 (S)+4HCl(l) 4 The chemical reaction of SnO 2 films coating is Reverse reaction is

5. SnO 2 Glass SnO 2 SnCl 4 +2 H 2 O SnO 2 +4HCl UV-Vis Spectrophotometer Atomic Force Microscope Four Point Probes 5 Experiment Percent transmission rms roughness Sheet resistance

6. Experimen t (Cont.) 6 Effect of etching concentration / etching time Effect of etching temperature / etching time

7. Table 1: Preparation conditions of etching time and HCl concentration at room temperature. Concentration (%) Etching time (min) 1, 3, 5 1, 5, 10, 15 7 Experiment( Cont.)

8. Results and Discussion Fig. 2. The relationship between the percent transmission and the etching times of the specimens etched at different concentration. 8 Optical properties

9. Morphological properties Results and Discussion 9 HCl 1% 1min Non etching Fig 3. 3-D images of spacimens HCl 5% 15min

10. Etching time (min) Con. (%) Roughness rms (nm) Roughness max (nm) Surface area (µm 2 ) non etched 32.40225.24 107.02 1 144.20387.00 121.79 5 1540.58339.95 125.13 Table 2: The roughness of specimen form AFM of relationship between etching concentration and etching time. Morphological properties Results and Discussion 10

11. 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. 11 Results and Discussion

12. Temperature ( o C) 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. 12 Experiment (Cont.)

13. Optical properties Fig. 5. The relationship between the percent transmission and the temperature of the specimens etched at different etching times. 13 Results and Discussion

14. 14 Non etching 50 o C 15 min 40 o C 1 min Morphological properties Fig. 6. 3-D images of spacimen Results and Discussion

15. T ( o C) Etching time (min) Roughness rms (nm) Roughness max (nm) Surface area (µm 2 ) non etched 32.40225.24 107.02 40 144.49346.28 128.28 50 1544.92390.89 130.96 Table 4: The roughness of specimen form AFM of relationship between temperature and etching time. Morphological properties Results and Discussion 15

16. Fig. 7. The relationship between the sheet resistance and the temperature of the specimens etched at different of etching times from 1-15 min. 16 Electrical properties Results and Discussion

17. Conclusio n 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. 17

18. Referenc es [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, 38 th Congress on Science and Technology of Thailand, Chiangmai, Thailand, (2012), p 162. 18

19. Acknowled gements Supattanapong Dumrongrattana Wandee Onreabroy Tula Jutarosaga Department of Physics Faculty of Science King Mongkut’s University of Technology Thonburi 19