本研究系統性探討釩（vanadium, V）取代式摻雜對二硒化鎢（WSe2）之振動、光學與電性的影響。以化學計量式VxW1−xSe2表示樣品，建立四種摻雜濃度（x = 0、0.002、0.003、0.005）與四種層數（單層至四層）共十六個樣品之系統性矩陣，進行拉曼光譜與光致發光光譜分析；並針對V0.003W0.997Se2之雙層與四層樣品，透過電子束微影（electron beam lithography, EBL）與反應性離子蝕刻（reactive ion etching, RIE）製作霍爾元件（Hall bar），進行電性量測。
拉曼光譜分析顯示，釩摻雜誘發 E_2g^1 、 A_1g 與 B_2g^1 三個振動模態之系統性紅移：顯示 V 原子取代 W 位點後可能造成局部鍵結環境改變，並降低有效鍵結力常數，使相關聲子模態呈現軟化現象。E_2g^1 紅移量隨層數增加而遞減（單層：1.47 cm⁻¹、四層：0.47 cm⁻¹），反映層間凡德瓦耦合對摻雜效應之穩定化作用。光致發光分析則顯示釩摻雜引發顯著之光譜紅移（單層約 60 meV、多層約 20–30 meV）、線形展寬與發光強度衰減，源於能帶重整化、能隙內缺陷態與非輻射復合通道之共同作用。電性量測結果顯示，雙層與四層元件均呈現雙極性傳輸行為，確認釩摻雜引入有效之受體能階。V0.003W0.997Se2之雙層元件具備較佳之閘極控制能力，四層元件則展現較高之場效遷移率與較大之開關電流比。
綜合上述結果，釩取代式摻雜於 WSe2 中所引發之鍵結軟化、晶格無序、能帶重整化等現象呈現相互呼應之物理機制，並隨層數展現顯著之相依行為。

This study systematically investigates the optical and electrical properties of vanadium-doped WSe2. V-doped WSe2 samples are denoted by VxW1−xSe2, where x is the fraction of W lattice sites substituted by V. A 4 × 4 sample matrix of four doping levels (x = 0, 0.002, 0.003, 0.005) and four layer thicknesses (monolayer to four-layer) was prepared for Raman and photoluminescence (PL) characterization, and Hall bar devices were fabricated from V0.003W0.997Se2 bilayer and four-layer flakes for electrical transport measurements at room temperature.
Raman analysis shows that V doping induces systematic redshifts in theE_2g^1,A_1g, and B_2g^1vibrational modes, suggesting that V substitution at W sites modifies the local bonding environment and reduces the effective force constant, leading to phonon softening. The E_2g^1 redshift magnitude decreases from 1.47 cm⁻¹ in monolayer to 0.47 cm⁻¹ in four-layer samples, evidencing the stabilizing influence of interlayer van der Waals coupling. PL spectroscopy further reveals a pronounced doping-induced redshift (~60 meV for monolayer, ~20–30 meV for multilayer), accompanied by linewidth broadening and emission quenching, arising from bandgap renormalization, in-gap defect states, and defect-mediated non-radiative recombination. Both bilayer and four-layer devices exhibit ambipolar transport behavior, confirming that V doping introduces effective acceptor states.
Overall, V substitution in WSe2 gives rise to bond softening, lattice disorder, band-structure modification, and acceptor-state formation, with pronounced layer-dependent behavior throughout.

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