以聚乙烯醇輔助化學氣相沉積法合成二硫化鉬鎢合金

Synthesis of MoxW1-xS2 by PVA-assisted Chemical vapor deposition

劉育伶(Yu-Ling Liu)

指導教授 ： 陳俊維

共同指導教授 ： 林麗瓊 ； 陳貴賢(Kuei-Hsien Chen)

國立臺灣大學/工學院/材料科學與工程學研究所/碩士(2022年)

https://doi.org/10.6342/NTU202200382

摘要

二維過渡金屬二硫族化物的摻雜技術是當前相當重要的課題，有效的摻雜方法將會大幅擴展此材料在各方面的應用。本實驗使用高分子輔助沉積法將金屬前驅物塗佈於藍寶石基板，並在化學氣相沉積系統中進行煅燒、預退火及硫化。使用高分子能確保金屬前驅物在基板上均勻地分散，並有效包裹金屬前驅物免於不必要的化學反應。欲摻雜過渡金屬原子時，此方法展現便利性，且摻雜原子與母相原子在溶液中均勻的混合有助於提升成功摻雜的可能性。同時，高分子輔助沉積法低成本、可塗佈於各種表面等特性，使其充分展現了應用潛力。
在本報告中，首先針對成長純二硫化鉬、二硫化鎢的實驗結果進行成長機制的討論，並探討兩種材料之間在成長上的差異。第二部分，我們基於這兩種材料的差異，在硫化前的退火階段調控氣氛，臨場改變反應中的蒸氣壓，以達到均勻的二硫化鉬鎢合金。此外，我們也將提出以高分子輔助沉積成長二硫化鉬－二硫化鎢平面異質結構以及大面積二硫化鎢的想法。

關鍵字

過渡金屬二硫族化物 ； 高分子輔助沉積法 ； 二硫化鉬－二硫化鎢平面異質結構 ； 二維材料摻雜 ； 二硫化鉬鎢合金

並列摘要

Doping technique plays a vital role in functionalizing 2D transition metal dichalcogenides (TMDC). We herein develop an advanced polymer-assisted growth to achieve the substitutional doping and alloying in TMDC. The PVA solution prepared by the mixture of host and dopant precursors was spin-coated onto sapphire substrates, followed by a one-pot synthesis process including calcination, pre-annealing, and sulfurization in the LPCVD system. In this method, the polymer binds the metal ions by hydrogen bonds, resulting in a uniform distribution of the metal precursors on the substrate and preventing any unwanted reaction in the air. This method also shows great feasibility in doping by simply adding different metal ions to the solution; meanwhile, mixing the precursors at the molecular level in a liquid-phase solution prior to CVD growth enhances the possibility of doping. Moreover, the excellent film-forming property of PVA makes the 2D materials scalable and applicable to various surfaces. Therefore, this new approach has great potential to be extended to other transition metal substitutional doping.
In this report, the growth mechanism of polymer-assisted CVD growth and the difference between MoS2 and WS2 in the growth aspect are firstly discussed. For the growth of MoWS2, we actively tune the atmosphere in the pre-annealing step to in-situ tune the vapor pressure of the two metal species, aiming to achieve the uniform MoWS2. In addition, we also propose the idea of growing MoS2-WS2 in-plane heterostructure and large-area WS2 by this method.

並列關鍵字

transition metal dichalcogenides ； 2D materials doping ； molybdenum tungsten disulfide ； MoS2-WS2 in-plane heterostructure ； polymer-assisted deposition

參考文獻

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