| 摘要: | 石墨烯（Graphene），具有優異的導電性、機械強度、光穿透率（ > 97%）和化學穩定性，在軟性電子與光電元件深具應用潛力。化學氣相沉積法（Chemical Vapor Deposition, CVD）於過渡金屬基材上成長石墨烯薄膜為目前的主流方法，具有大面積薄膜、高結晶性及高均勻性的優點。然而，大面積轉印石墨烯薄膜仍是目前進入工業上實際應用的瓶頸。
本研究將利用CVD法，成長大面積、多層的高品質石墨烯薄膜，並研究可靠之轉印技術，將石墨烯薄膜直接轉印至高透光之軟性基板上。達到高值性軟性基板的開發，未來可應用於高透光、高化學穩定性、耐高溫、可彎曲之導電膜、導熱與感測元件等。
本研究之具體成果: (1) 發展石墨烯多層膜(MLG)的直接合成技術，優化條件達到2-3層均勻的石墨烯薄膜，高結晶性(ID/IG ≈ 0.12)及導電膜光電特性(Rs: 800 ohm/sq，at 550 nm T: 94%); (2) 發展捲對捲機械撕離技術(R2RME)於製作石墨烯薄膜於各種軟性基板條件的系統性研究， R2RME優化之條件測試(張力、分離角度等)，搭配後期所開發的電化學插層與剝離技術(EC-DME)，可進一步提升轉印良率、均勻性和降低片電阻值。(3)研究石墨烯轉印於軟性基板後的各種改質方法，系統性的探討其對於降低片電阻的影響，使用化學改質方法修飾石墨烯，結果顯示(i)單層石墨烯可達到光穿94%，片電阻57 ohm/sq； (ii) 利用EC-R2RME乾式轉印法結合化學改質可將片電阻降低至~290 ohm/sq，光穿~85%(含基板)。
總結此研究的效益，本研究利用各種所開發之接著劑，能夠直接將石墨烯薄膜由銅箔上直接剝離下來，並能維持其導電膜的性能，此研究獲得一個突破性且具有量產性的乾式轉印技術，能大幅降低成本與環保製程的目標。
;Graphene, which has exceptional electrical, mechanical, transparency and chemical stability properties, has potential to be applied to flexible electronic and optoelectronic device. Using Chemical Vapor Deposition (CVD) to synthesize graphene film on transition metals is the main method for producing large area, highly crystalline, and uniform graphene film. However, transferring large area graphene films is still a critical issue for graphene applying in industrial-scale production.
In this research, we use CVD to synthesize large area and high-performance multilayer graphene films. Furthermore, we invest the dry transfer method to transfer graphene films on a flexible substrate in order to develop high-performance flexible substrate which can be applied to high transparency, high chemical stability, temperature resistant and flexible electrical conductive film.
Results of this research are as follows. (1) Directly synthesize 2~3 uniform multilayer graphene that is highly crystalline (ID/IG ≈ 0.12) and high optoelectronic performance (Rs: 800 ohm/sq, at 550 nm T: 94%). (2) Using Roll to Roll Mechanical Exfoliation method (R2RME) to transfer graphene films onto different flexible substrates. Combining the optimized conditions (tension and tear angle, etc.) of R2RME and Electrochemical can increase the yield, uniformity, and conductivity of graphene films. (3) Doping graphene films that have been transferred onto flexible substrates. We use different kinds of chemical doping methods to modify graphene films and discuss how they make influences on sheet resistance. Following are the results of this work. (i) The sheet resistance and transmittance of the single layer graphene film can reach 57 ohm/sq and 94%, respectively. (ii) Combining EC-DME dry transfer method with chemical doping can make the sheet resistance decrease to ~290 ohm/sq , transmittance ~85% (including the substrate)
In summary, with different kinds of binder developed in this research, we can directly exfoliate graphene films from Cu foil and retain the properties of the conductive film. This is an industrial-scale production dry transfer method, which can lower the cost of production and is eco-friendly. |
