不同應力下之石墨烯電特性研究

Study of Electrical Properties of Strained Graphene

黃雨平(Yu-ping Huang)

指導教授 ： 紀國鐘 ； 鄭劭家

國立中央大學/理學院/物理學系/碩士(2014年)

摘要

在本論文中，利用化學氣相磊晶法成長高品質石墨烯，並利用濕蝕刻轉印法，轉印石墨烯至軟性塑膠基板(PET)上，利用彎曲軟性塑膠基板施加應力於石墨烯，再使用霍爾量測系統，量測石墨烯在不同應力下之電特性變化。
在石墨烯之電特性表現上，當施加應力於石墨烯時，石墨烯之片電阻，在第一次施加應力下會快速上升，當釋放施加於石墨烯上之應力時，石墨烯之片電阻並無回復至原來的電阻值，當第二次施加應力至與第一次之應力相同時，石墨烯之片電阻並無改變，當釋放應力時，石墨烯之片電阻與第一次釋放應力時一樣，並無改變，第三次施加應力之情況與第二次相同，當施加之應力大於上一次所施加之應力時，石墨烯之片電阻與上一次施加應力相較下增加。
當施加應力於不同起始片電阻之石墨烯時，石墨烯片電阻上升之比例，為樣品改變之長度約二次方增加，推測其原因可能為彎曲樣品施加應力於石墨烯時，使石墨烯受到拉伸，造成石墨烯之缺陷增加，以致於石墨烯之片電阻上升，石墨烯之載子漂移率，隨著石墨烯之缺陷增加，造成載子散射增加，以致於石墨烯之載子漂移率隨電阻增加而減少，石墨烯之載子濃度，當石墨烯所受之應力增加時，石墨烯之載子濃度隨應力增加而增加，當釋放石墨烯所受之應力時，石墨烯之載子濃度回復至未受應力時之值。

關鍵字

石墨烯 ； 應力 ； 片電阻 ； 載子遷移率 ； 片載子濃度

並列摘要

In this thesis, the graphene were grown by chemical vapor deposition. And using wet transfer that graphene were transferred from copper to PET. Then strain exerted to graphene by bending the PET substrate. The electrical property of graphene was measured by Hall measurement system.
The sheet resistivity of graphene was increased rapidly that strain exerted on graphene at first. When the strain exerted on graphene released, the sheet resistivity of graphene was not changed. In the second times and third times that strain exerted on graphene, the sheet resistivity of graphene was not changed. When the strain exerted on graphene bigger than last times, the sheet resistivity of graphene was higher than last times. For the graphene with various initial sheet resistivity`s, the sheet resistivity of graphene were changes with square of the change in sample length. The reason is that the length of graphene was changed with the length of sample was changed. The change in length of graphene, due to the defects of graphene increased. The defects of graphene increase, the sheet resistivity of graphene increased. The mobility of graphene is increased with the defects increased. The carrier scattering of graphene were increased with the defects of graphene increased. The carrier concentration of graphene is increased with the graphene be strained. The carrier concentration of graphene is return to initial with the strain of graphene release.

參考文獻

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