二維材料近年來被視為下一世代的半導體材料，有別於三維材料，
二維材料能以單原子層結構穩定存在，並且具備良好的物性與電性，
可縮小現有的場效電晶體體積，提高晶片效能；除此之外，二維材料
也能做為新穎的替代能源材料，將二氧化碳轉化成碳氫化合物，並且
可透過釩摻雜來提高催化效率，期望改善全球暖化問題。
本實驗研究的二維材料為屬於過渡金屬二硫族化合物(TMDCs)中
的二硫化鉬，並著重於合成釩摻雜之二硫化鉬的方法，二硫化鉬不僅
可應用於光電元件，亦可做為觸媒材料，若想將二硫化鉬應用於工業
上，則需要合成大面積且連續均勻的薄膜，故此研究使用創新的合成
方法: 覆蓋氣-液-固態方法來製備釩參雜之二硫化鉬薄膜，首先在矽
基板上沉積四層前驅物薄膜，依序為:三氧化鉬、五氧化二釩、氟化鈉、
二氧化矽薄膜，二氧化矽薄膜做為覆蓋層及擴散膜，防止氧化釩蒸發
消失跟控制氣體硫的擴散，對於釩摻雜是重要的一環，若沒有二氧化
矽覆蓋層，釩將無法成功的摻雜進二硫化鉬中；在硫化過程中氧化鉬、
氧化釩與氟化鈉先反應形成鹽類液體後，氣態硫再穿過二氧化矽覆蓋
層來與鹽類液體反應，最後過飽和析出釩摻雜二硫化鉬薄膜；此方法
因牽涉到鹽類液態反應，因此能合成高摻雜濃度的二硫化鉬薄膜。

Transition metal dichalcogenides (TMDs) have attracted people’s
attention due to their outstanding physical properties. Molybdenum
disulfide (MoS 2 ) thin film has been particularly found unique applications
in catalysis, optoelectronics, transistors, and energy storage. These
applications demand a large-scale synthesis of MoS 2 thin film with uniform
thickness and high crystallinity. Besides, dopants in two-dimensional
dichalcogenides have a significant role in affecting electronic, mechanical,
and interfacial properties. Controllable doping is desired for the intentional
modification of such properties to enhance performance. Vanadium-doing
could enhance MoS 2 conductivity and carrier concentration so that it can
improve catalytic activity. In this report, a new capping vapor-liquid-solid
(VLS) synthesis has been developed. Depositing MoO 3 , V 2 O 5 , NaF and
SiO 2 on SiO 2 /Si wafer sequentially as a 4-layer precursor. Herein, SiO 2 acts
as capping layer and diffusion membrane, which is critical for V-doping.
During sulfurization, MoO 3 , V 2 O 5 and NaF will form Mo/V/Na salt liquid
first. Then sulfur will diffuse through capping SiO 2 layer and dissolve in
Na salt liquid. Finally, V-MoS 2 will oversaturated on the substrate. After
that, HF etching process is used to remove capping SiO 2 layer and V-MoS 2
will show on the centimeter-scale wafer.

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