近年來，石墨烯奈米帶由於其獨特的物理和電學特性在微電子領域有著巨大的應用前景。在各種的研究中，改變電性是我們有興趣想探討的主題。而改變方法有許多種，在奈米帶表面吸附非碳原子是有效其中之一。
本論文為使用VASP材料模擬程式，運用第一原理來計算，將石墨烯奈米帶表面吸附鹼金屬原子，改變奈米帶的寬度或鹼金屬吸附的濃度，討論幾何結構、能帶、電荷密度和態密度。從幾何結構得知最佳吸附位置、鍵長、吸附能的變化。而能帶則是給出吸附後變為帶有自由載子的金屬、導電電子主要為哪種原子貢獻、載子濃度大小，並與簡單的化學圖象計算的載子濃度比對加以驗證。電荷密度可與吸附能、鍵長、態密度定性上的成正比的趨勢，藉此分析得知吸附最穩定的鹼金屬為鋰原子。

The models based on the first-principles calculation are used to study the electronic properties of graphene nanoribbons. The width variation of the nanoribbon and different degrees of alkali metal adsorption provide means to create some peculiar effects. It is revealed from the band structure that alkali metals or carbons are the main contributors for the free electrons. The densities of free carriers are obtained from the crossing points where the conduction bands are intercepted by the Fermi level. As compared with the results from the theoretical chemistry, there is a good match between the linear carrier density formula and the energy band theory. The stability of the geometric structure due to the adsorption of alkali atoms can correspond to the adsorption energies, the variations of charge density differences, and the extra DOS peak magnitudes near the Fermi energy.

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