石墨烯在近年來因其新穎及特殊性質而廣泛地受到各領域的重視。但是石墨烯的主要製備方法化學氣相沉積相當耗時且無法大規模生產，影響其應用之可能性。因此我們積極尋找取代方法，而噴塗沉積是有潛力的製程之一。石墨烯噴塗沉積有以下優勢可取代化學氣相沉積：(1)節省材料(2)製程時間短且容易準備(3)可進行大規模製造。然而其缺點是受到基板溫度和噴塗解析度的限制而無法製造較精細的結構。因此我們應用雷射的特性加熱基板幫助噴塗沉積，期望能克服以上缺點。

在本實驗中，我們首先探討影響噴塗沉積的參數，找出最穩定的組合，並進一步使用雷射在噴塗沉積進行時加工，觀察並分析其變化。我們做法的優點可應用在透明導電薄膜、可撓式電子元件或其他領域之中。

Graphene has attracted great attention in both fundamental and applied research. The reason why scientists are interested in graphene is due to its novel and unique properties. The main method to produce graphene thin films is Chemical vapor deposition (CVD). However, CVD process is time consuming and expensive. We therefore need to find a more practical method. Spray deposition can be a potential method to replace CVD because of its inexpensive, fast, and easy characteristics and its scalability. Although spray deposition has many benefits, it still has challenges which are the required high temperature of the substrate and a limited spraying resolution. We here show that using a laser to assist spray deposition can improve these issues.

In our experiment, we first discuss the parameter which affect the spray deposition and find the most stable combination. Then we apply the laser to assist spray deposition and analyze its feature. The benefits of our method can be used in many applications, e.g. transparent conductive film and flexible electronics, in the future.

1. Arico, A.S., et al., Nanostructured materials for advanced energy conversion and storage devices. Nature Materials, 2005. 4(5): p. 366-377.
2. Nel, A., et al., Toxic potential of materials at the nanolevel. Science, 2006. 311(5761): p. 622-627.
3. Simon, P. and Y. Gogotsi, Materials for electrochemical capacitors. Nature Materials, 2008. 7(11): p. 845-854.
4. Boehm, H.P., et al., DAS ADSORPTIONSVERHALTEN SEHR DUNNER KOHLENSTOFF-FOLIEN. Zeitschrift Fur Anorganische Und Allgemeine Chemie, 1962. 316(3-4): p. 119-127.
5. Novoselov, K.S., et al., Electric field effect in atomically thin carbon films. Science, 2004. 306(5696): p. 666-669.
6. Geim, A.K. and P. Kim, Carbon wonderland. Scientific American, 2008. 298(4): p. 90-97.
7. de Andres, P.L., R. Ramirez, and J.A. Verges, Strong covalent bonding between two graphene layers. Physical Review B, 2008. 77(4): p. 5.
8. Tsoukleri, G., et al., Subjecting a Graphene Monolayer to Tension and Compression. Small, 2009. 5(21): p. 2397-2402.
9. Lee, C., et al., Measurement of the elastic properties and intrinsic strength of monolayer graphene. Science, 2008. 321(5887): p. 385-388.
10. Nair, R.R., et al., Fine structure constant defines visual transparency of graphene. Science, 2008. 320(5881): p. 1308-1308.
11. Charlier, J.C., et al., Electron and phonon properties of graphene: Their relationship with carbon nanotubes, in Carbon Na Notubes: Advanced Topics in the Synthesis, Structure, Properties and Applications, A. Jorio, G. Dresselhaus, and M.S. Dresselhaus, Editors. 2008, Springer-Verlag Berlin: Berlin. p. 673-709.
12. Morozov, S.V., et al., Giant intrinsic carrier mobilities in graphene and its bilayer. Physical Review Letters, 2008. 100(1): p. 4.
13. Li, X.S., et al., Large-Area Synthesis of High-Quality and Uniform Graphene Films on Copper Foils. Science, 2009. 324(5932): p. 1312-1314.
14. Kim, K.S., et al., Large-scale pattern growth of graphene films for stretchable transparent electrodes. Nature, 2009. 457(7230): p. 706-710.
15. Bae, S., et al., Roll-to-roll production of 30-inch graphene films for transparent electrodes. Nature Nanotechnology, 2010. 5(8): p. 574-578.
16. Bae, S., et al., Towards industrial applications of graphene electrodes. Physica Scripta, 2012. T146: p. 8.
17. Spin Coating: A Guide to Theory and Techniques. Available from: https://www.ossila.com/pages/spin-coating.
18. Pulker, H.K., Coatings on Glass (Second Edition).
19. Filipovic, L., et al., Methods of simulating thin film deposition using spray pyrolysis techniques. Microelectronic Engineering, 2014. 117: p. 57-66.
20. Perednis, D. and L.J. Gauckler, Thin Film Deposition Using Spray Pyrolysis. Journal of Electroceramics, 2005. volume: p. 8.
21. Sageev, G. and J.H. Seinfeld, Laser heating of an aqueous aerosol particle. APPLIED OPTICS 1 December 1984. Vol. 23, No. 23
22. Armstrong, R.L., Aerosol heating and vaporization by pulsed light beams. APPLIED OPTICS, 1 January 1984 Vol. 23, No. 1.
23. Zardecki, A. and S.A.W. Gerstl, High- energy laser- assisted imaging through vaporizing aerosolsOptical, Infrared, and Millimeter Wave Propagation Engineering (1988). SPIE Vol. 926.
24. Kafalas, P. and J. A. P. Ferdinand, Fog Droplet Vaporization and Fragmentationby a 10.6-um Laser Pulse. APPLIED OPTICS, January 1973. Vol. 12, No. 1
25. Surface tension values of some common test liquids for surface energy analysis. Available from: http://www.surface-tension.de/.
26. accu dyne test. Viscosity, Surface Tension, Specific Density and Molecular Weight of Selected Liquids; Available from: https://www.accudynetest.com/visc_table.html.
27. Properties of Solvents on Various Sorbents. Available from: http://www.sanderkok.com/techniques/hplc/eluotropic_series_extended.html.
28. Lotya, M., et al., Liquid Phase Production of Graphene by Exfoliation of Graphite in Surfactant/Water Solutions. Journal of the American Chemical Society, 2009. 131(10): p. 3611-3620.
29. Coleman, J.N., Liquid Exfoliation of Defect-Free Graphene. Accounts of Chemical Research, 2013. 46(1): p. 14-22.
30. Li, J.T., et al., Efficient Inkjet Printing of Graphene. Advanced Materials, 2013. 25(29): p. 3985-3992.
31. Deegan, R.D., et al., Contact line deposits in an evaporating drop. Physical Review E, 2000. 62(1): p. 756-765.
32. Park, J. and J. Moon, Control of colloidal particle deposit patterns within picoliter droplets ejected by ink-jet printing. Langmuir, 2006. 22(8): p. 3506-3513.
33. Eur. Ing., F. Ceng, and J.C. Ion, Laser Processing of Engineering Materials Principles, Procedure and Industrial Application.
34. Eftekhari, A. and P. Jafarkhani, Curly Graphene with Specious Inter layers Displaying Superior Capacity for Hydrogen Storage. Journal of Physical Chemistry C, 2013. 117(48): p. 25845-25851.
35. la-sight. Precision, Speed & Safety; Available from: http://www.la-sight.com/lasik-prk/Wavelight/precision-speed-safety.
36. Smith, G.N., K. Kalli, and K. Sugden, Advances in Femtosecond Micromachining and Inscription of Micro and Nano Photonic Devices. Frontiers in Guided Wave Optics and Optoelectronics: p. 26.