過渡金屬二硫族化物(TMD)因其出色的電子特性以及二維的傳輸特性在，是低維半導體元件的熱門候選，經實驗證明，單層過渡金屬二硫族化物電子遷移率可達到200 $cm^2/V\cdot s$。然而，由於嚴重的費米能級釘扎和接觸金屬工程的困難，使的這類材料的元件接觸電阻很高。一種解決方案是在接觸區域進行摻雜。因此了解摻雜的影響變得非常重要。

在這項工作中，我們採用第一性原理計算來研究選定的 n 型和 p 型替位摻雜原子在單層二硒化鎢(WSe$_2$) 中的弛豫結構、形成能和電子特性。首先，我們檢查每種摻雜原子的造成的二硒化鎢結構弛豫情況，以獲得結構變化的清晰圖像。其次，我們計算每種摻雜原子的形成能，以獲得摻雜原子在材料成長中是否適當。第三，我們重點研究 Hf、V、Nb、Ta 和 P 摻雜原子，了解它們對電子結構的影響。此外，我們研究了自旋軌道耦合、摻雜原子引起的應變和不同摻雜濃度對電子結構的影響。參雜二硒化鎢是持續研究中的項目，這項工作可以為二硒化鎢摻雜原子的選擇提供一些方向。

Transition metal dichalcogenides (TMDs) are known for their application in semiconductor devices due to their excellent electronic properties and low-dimens-\\
\noindent
ional transport. It has been shown that the mobility can reach 200 $cm^2/V\cdot s$. However, the contact resistance of TMDs' devices are high due to severe Fermi level pinning and the difficulties of contact engineering. One solution is doping in the contact region. Therefore, understanding the influence of doping becomes important.

In this work, we adopt first-principles calculations to investigate the structural, formation energy, and electronic properties of selected n-type and p-type substitutional dopants in monolayer WSe$_2$. First, we examine the relaxation of each dopant to obtain a clear picture of the structural changes. Second, we calculate the formation energy of each dopant. Third, we focus on Hf, V, Nb, Ta, and P dopants to understand their influence on the electronic structure. Furthermore, we study the effects of spin-orbit coupling, strain caused by dopants, and doping concentration on the electronic structure.

Doping in WSe$_2$ is on-going research, and we believe this work can provide valuable guidance for WSe$_2$ dopant selection.

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