利用自我封蓋固液氣化學氣相沉積法成長單層二硫化鉬

Monolayer Molybdenum Disulfide Growth by Self-Capping Vapor-Liquid-Solid Mechanism under Chemical Vapor Deposition

陳緯在(Wei-Zai Chen)

指導教授 ： 陳俊維

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/NTU202200023

摘要

擁有些許能帶差的半導體二維材料過渡金屬二硫屬化合物系列 (transition metaldichalcogenides,TMD) 為近年來相當熱門的研究主題，其中具有1.8eV直接 能帶的單層二硫化鉬具有許多特別的物理、化學性質，為一相當知名且相當具有發 展性的二維奈米材料。在二硫化鉬的製作中，化學氣相沈積法能在合理的成本下產 出高品質、大面積且層數均勻的二維二硫化鉬，是近年來最被普遍使用的一種生長 方式。在一般使用粉末作為前驅物的固氣氣成長機制 (Vapor-Solid-Solid,VSS) 中， 通常會選擇降低粉末的使用量來降低成長時的核點密度並成長出較大晶粒的二硫 化鉬，與此同時，二硫化鉬的覆蓋率也會大幅下降，而降低其實用性。我們選擇用 相當新穎的自我封蓋固液氣成長機制 (Self-Capping Vapor-Liquid-Solid, SCVLS) ， 透過共晶反應提供均勻的液態前驅物並擁有快速的成長速率，其能成長出比固氣 氣成長機制更大晶粒、更大覆蓋範圍、且層數均勻度、結晶、電子性質都更好的二 硫化鉬奈米片或薄膜。在本篇論文中，我們能透過 SCVLS 成長機製能成長出晶粒 約為 200μm 的單層二硫化鉬奈米片或是 1×1 cm2 覆蓋的單層二硫化鉬薄膜。

關鍵字

過渡金屬二硫屬化合物 ； 二硫化鉬 ； 化學氣相沉積法 ； 自我封蓋固液氣成 長機制

並列摘要

With suitable band gap energy, TMDs (Transition Metal Dichalcogenides) have been one of the most popular research topics. Among TMDs, monolayer MoS2 with 1.8 eV direct band gap shows several special physical and chemical properties and has become a famous and seminal 2-dimentional nanomaterial. Chemical vapor deposition could be used to fabricate MoS2 with high quality, high coverage and high layer-uniformity in reasonable costs, and has become one of the most common method. In CVD, extremely low amounts of powder precursor is used in VSS (Vapor-Solid-Solid) mechanism for lower nucleation sites and larger MoS2 grain size, while the coverage of MoS2 could be lower and the practicality would be reduced at the same time. Thus, we chose the novel SCVLS (Self-Capping Vapor-Liquid-Solid) mechanism, with uniform liquid precursor supplied from eutectic reaction and with high growth rate, to fabricate MoS2 nanosheets or films with larger grain size, higher coverage, higher layer uniformity, better crystalline and electric properties than that fabricated by VSS mechanism. We fabricated the monolayer MoS2 nanosheets with grain size around 200μm and full-coverage MoS2 film in 1×1 cm2 substrates by this SCVLS mechanism.

並列關鍵字

Transition Metal Dichalcogenides ； Molybdenum disulfide ； Chemical Vapor Deposition ； Self-Capping Vapor-Liquid-Solid mechanism

參考文獻

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