單原子層二硒化鉬之成長及分析

Synthesis and characterizations of MoSe2 monolayer

陳宗廷(Chen,Chung Ting)

指導教授 ： 李奕賢

國立清華大學/工學院/材料科學工程學系/碩士(2015年)

摘要

二硒化鉬為TMD二維材料家族成員之一，其單層結構達奈米尺度，具有獨特的光、電性質。本研究成功利用常壓化學氣相沉積法合成二硒化鉬在二氧化矽/矽與三氧化二鋁基板上，並利用拉曼光譜及光致發光光譜鑑定生長之二硒化鉬品質；在光致發光光譜檢測中顯示，單層的二硒化鉬與數層的比較之下，，具有較高的發光強度且顯示能隙約1.56 eV 。根據調控不同生長參數的實驗結果，討論可能影響製程的因素，提供合成二硒化鉬的原則。此外，本研究將單層二硒化鉬製作成下閘極式場效電晶體，其中二硒化鉬在常溫下的載子遷移率可達0.9 cm2 V−1 s−1；將此元件作光偵測測試，二硒化鉬擁有良好的光響應，約為43.21 mA/W(使用功率為2.47×〖10〗^(-4) W的633 nm紅光雷射，在閘極電壓為-5 V時進行量測)，從此研究結果顯示出二硒化鉬在光偵測器的應用上，是具有潛力的材料之一。

關鍵字

二硒化鉬 ； 化學氣相沉積法

並列摘要

Single-layer molybdenum diselenide(MoSe2), a two-dimension material which possesses unique optical, electrical property of transition dichalcogenides in their layered form, and a dimension with nano-scale level. In this work, high crystalline MoSe2 monolayered atomic layers on SiO2/Si and sapphire substrates have been successfully synthesized by the chemical vapor deposition (CVD) method at atmospheric pressure. Raman spectroscopy reveals that the as-grown ultrathin MoSe2 layers change from single layer to few layers. Photoluminescence (PL) spectroscopy demonstrates that while the multi-layers MoSe2 show weak emission peak, the monolayer has a much stronger emission peak at ~1.56 eV. Our results provide some general guidelines for MoSe2 monolayer synthesis. In addition, we report on the fabrication and optoelectronic properties of phototransistors based on monolayered MoSe2 back-gated field-effect transistors, with a mobility of 0.9 cm2 V−1 s−1 at room temperature. The devices exhibit a good photoresponsivity of 43.21 mA/W (using a 633 nm laser at a laser power of 2.47×〖10〗^(-4) W and a gate bias of -5 V)suggesting that MoSe2 monolayer is a promising material for photodetection applications.

並列關鍵字

MoSe2 ； chemical vapor deposition (CVD) method

參考文獻

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