石墨烯是由碳原子呈現六角蜂巢形狀的平面結構，而碳原子與碳原子相互間之間的長度為0.142 nm，石墨烯的厚度即為碳原子的厚度0.345 nm，因其優秀的性質被廣泛地運用在各整領域上，而本研究將針對石墨烯的熱傳導係數進行量測。
本研究將會使用拉曼光譜儀進行實驗量測，由於石墨烯的拉曼光譜圖會在位置1580 cm^−1會形成一個波峰，稱之為G peak，且此波峰的位置變化與雷射功率呈現線性關係，因此可以利用此特性來推算石墨烯的熱傳導係數，並針對影響熱傳導係數的原因進行探討。
本研究利用化學氣相沉積法進行石墨烯的製備，此制備方法容易獲得高品質的石墨烯且厚度可以達到1到2層，經過實驗的量測單層石墨烯的熱傳導係數為2800~3200(W/mK)，而雙層石墨烯熱傳導係數為1600~2100(W/mK)，由此結果可以發現當石墨烯的層數越多時，其熱傳導係數會降低，且當層數越多其熱傳導係數會越接近高定向熱解石墨(HOPG)，高定向熱解石墨的碳原子堆疊方式具有規則與周期性，因此當石墨烯層數越多時，其熱傳導係數會越接近，由此結果可以知道層與層之間也會造成熱傳導係數的影響，當原子間的排列越混亂且無規則性熱傳導係數會降低。

Graphene, a two-dimensional structure composed of carbon atoms arranged in a hexagonal honeycomb lattice and hybridized in an sp² orbital, possesses numerous outstanding properties such as high mechanical strength, high electron mobility, high thermal conductivity, and high transparency. Therefore, graphene finds wide applications in various fields, including aerospace industry, biotechnology, integrated circuits, and clean filtration technologies, among others. Thin film processing is widely used in semiconductor, optoelectronics, microelectromechanical systems (MEMS), and other fields.
In this research, Raman spectroscopy is employed to measure the thermal conductivity of graphene. This spectroscopic method relies on the Raman scattering phenomenon, which occurs when incident light interacts with sample molecules, resulting in a frequency shift of the scattered light compared to the incident light. Different materials exhibit distinctive vibrational information, making Raman spectroscopy a valuable tool for characterizing material structures. By analyzing the Raman spectra, a G peak is observed at a position of 1580 cm-1, and the position of this peak exhibits a linear relationship with laser power. This characteristic can be utilized to estimate the thermal conductivity of graphene, and the number of graphene layers can also be determined from the Raman spectra.
Experimental measurements indicate that the thermal conductivity of monolayer graphene is in the range of 2800 to 3200 (W/mK), while bilayer graphene exhibits a thermal conductivity of 1600 to 2100 (W/mK). From these results, it is observed that as the number of graphene layers increases, the thermal conductivity decreases. Moreover, as the number of layers increases, the thermal conductivity approaches that of HOPG. HOPG has a regular and periodic arrangement of carbon atoms, and therefore, as the number of graphene layers increases, the thermal conductivity approaches a similar value due to the regular stacking of carbon atoms. This indicates that the arrangement of atoms between layers also influences thermal conductivity, and a more disordered and irregular arrangement leads to a decrease in thermal conductivity.

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