本文選題：二維材料　切入點(diǎn)：二硫化鉬　出處：《中國(guó)科學(xué)院研究生院(上海技術(shù)物理研究所)》2016年博士論文　論文類型：學(xué)位論文

【摘要】：過去的十幾年來,石墨烯因優(yōu)異的機(jī)械、光學(xué)、電學(xué)特性受到了極大的關(guān)注,且在光電子與微電子等領(lǐng)域的應(yīng)用潛力巨大。近年來,過渡金屬硫族化合物二維原子晶體材料展現(xiàn)了許多石墨烯所不具有的物理特性,廣泛研究表明其在晶體管、光探測(cè)器、光伏電池等方面具有極大的應(yīng)用前景。本論文面向過渡金屬硫族化合物二維原子晶體材料的可控制備與范德瓦爾斯異質(zhì)結(jié),重點(diǎn)研究了二硫化鉬二維原子晶體材料的氣相生長(zhǎng)與復(fù)合,以及基于單層二硫化鉬原子晶體的二維范德瓦爾斯異質(zhì)結(jié)的特性與應(yīng)用。在以下幾個(gè)方面取得了重要的階段性進(jìn)展:(1)類石墨烯二硫化鉬生長(zhǎng)與機(jī)理方面:通過氣固輸運(yùn)方法和化學(xué)氣相沉積(CVD)方法成功制備出單層二硫化鉬;發(fā)現(xiàn)了二硫化鉬二維層狀材料生長(zhǎng)過程中局域范德華作用力自發(fā)誘導(dǎo)的非對(duì)稱應(yīng)變。研究發(fā)現(xiàn)氣固輸運(yùn)法生長(zhǎng)溫度較高且窗口較窄,反應(yīng)過程對(duì)氧氣較為敏感,二硫化鉬二維原子晶體尺寸100μm以下;CVD方法對(duì)襯底依賴性小,可生長(zhǎng)出尺寸大于100μm的單晶樣品。此外,兩種方法所制備的二維層狀材料都具有均勻的厚度、元素分布,較高的晶體質(zhì)量,優(yōu)異的光致熒光。觀察到二硫化鉬二維層狀材料中局域化范德瓦爾堆疊結(jié)構(gòu),通過拉曼光譜以及第一性原理模擬結(jié)果證明了局域化范德瓦爾堆疊的方式會(huì)在樣品中產(chǎn)生軸向應(yīng)力,并且估算出這個(gè)應(yīng)力大約在0.5%左右,PL峰位的移動(dòng)證明了這種局域化范德瓦爾相互作用會(huì)對(duì)此材料的光學(xué)帶隙有明顯的調(diào)控作用。這表明在這種超薄二硫化鉬材料中即使沒有外加應(yīng)力而通過有限的晶體邊界以及層間相互作用會(huì)對(duì)層間結(jié)構(gòu)有顯著的影響�；诙S層狀材料模塊化層層堆積的可控制性,這種局域化的范德瓦爾斯堆疊同樣提供了一種調(diào)控材料本征物理性能的方法,而避免了外加應(yīng)力的繁瑣和不便。(2)類石墨烯二硫化鉬材料的復(fù)合:通過CVD方法制備單層MoS2(1-x)Se2x,Mo(1-x)WxS2復(fù)合材料,并用液相方法把一維納米結(jié)構(gòu)生長(zhǎng)在二維單層結(jié)構(gòu)上,實(shí)現(xiàn)了對(duì)二硫化鉬材料的結(jié)構(gòu)與特性的調(diào)控。本論文討論了兩種基于二硫化鉬的復(fù)合材料,第一種是采用CVD方法通過渡金屬硫化物相互摻雜的方式制備的合金化的單層MoS2(1-x)Se2x,Mo(1-x)WxS2材料,通過控制摻雜原料的比例可以精細(xì)的調(diào)控?fù)诫s濃度,同時(shí)證明了用Raman光譜的手段可以準(zhǔn)確地判斷出摻雜元素的種類以及估算出摻雜濃度。經(jīng)過PL測(cè)試分析,我們證明了通過這種方式可以將摻Se、W的合金化單層材料的帶隙從1.55 eV(MoSe2)到1.97 eV(WS2)精細(xì)調(diào)控,從而滿足不同功能的需求。由于PL峰位對(duì)摻雜濃度非常敏感,因此可以通過測(cè)量合金化后PL峰位的偏移幅度反向推算摻雜濃度。第二種是采用CVD和水熱法結(jié)合的方式制備出二硫化鉬/氧化鋅納米棒復(fù)合結(jié)構(gòu),證明了單層二硫化鉬不僅可以較好的作為氧化鋅納米棒生長(zhǎng)的種子層,不會(huì)導(dǎo)致相互的晶格畸變,而且可以保證氧化鋅納米棒垂直生長(zhǎng)的趨向性,而氧化鋅在這種復(fù)合結(jié)構(gòu)中起到“天線”的光聚焦效果,使得底部二硫化鉬的光學(xué)信號(hào)被增強(qiáng)。這種復(fù)合結(jié)構(gòu)中兩種材料性能互相融合,相得益彰,是二維納米材料和一維材料相互復(fù)合提升性能的典型例子。(3)基于單層二硫化鉬超薄范德瓦爾斯異質(zhì)結(jié)研究方面:設(shè)計(jì)并驗(yàn)證了MoTe2/MoS2二維單層II類異質(zhì)結(jié)中的層間紅外躍遷,并獲得了二維異質(zhì)結(jié)紅外探測(cè)原型器件。利用自搭建的轉(zhuǎn)移平臺(tái)首次制備了單層MoTe2/MoS2異質(zhì)結(jié)樣品,理論計(jì)算和KPFM結(jié)果表明其能帶組合方式為II類構(gòu)型,與一些文獻(xiàn)的預(yù)判符合一致,我們用Raman光譜、PL光譜觀測(cè)到了MoTe2/MoS2之間強(qiáng)烈的層間耦合相互作用。利用KPFM測(cè)試手段首次在單層MoTe2/MoS2異質(zhì)結(jié)中觀測(cè)到光生載流子的產(chǎn)生和分離,證實(shí)了我們制備的這種超薄范德瓦爾斯異質(zhì)能夠?qū)崿F(xiàn)電學(xué)功能。利用單層MoTe2/MoS2異質(zhì)結(jié)制備了光響應(yīng)測(cè)試的原型器件,測(cè)試結(jié)果表明MoTe2/MoS2異質(zhì)結(jié)突破了純單層MoTe2和MoS2的光響應(yīng)截止波段,利用II類帶間激發(fā)對(duì)1550 nm波段同樣能夠?qū)崿F(xiàn)光響應(yīng)。這預(yù)示了II類原子層的范德瓦爾斯異質(zhì)結(jié)同樣可以實(shí)現(xiàn)層間激發(fā),在光探測(cè)方面有進(jìn)一步研究的價(jià)值。
[Abstract]:Over the past ten years, graphene has excellent mechanical, optical and electrical properties has attracted great attention, and the potential application in the field of Optoelectronics and microelectronics is huge. In recent years, transition metal chalcogenides two-dimensional atomic crystals materials exhibit physical properties of graphene do not have many, extensive research shows that the a transistor, a light detector, has great application prospect of photovoltaic cell and so on. This paper can control for transition metal chalcogenide materials by two-dimensional atomic crystals and Van Der Waals heterojunction, focusing on two molybdenum sulfide two-dimensional atomic crystal material vapor growth and composite, and the properties and application of two-dimensional Van Der Waals heterojunction single-layer atom based on crystal. Made progress in the following aspects: (1) graphene like MoS2 and growth mechanism: Pass Gas solid transport method and chemical vapor deposition (CVD) method was successfully prepared by single MoS2; found asymmetric strain MoS2 two-dimensional layered material growth process induced by spontaneous local Fan Dehua force. The study found that the gas-solid transport growth method and high temperature window is narrow, the reaction process is sensitive to oxygen, molybdenum disulfide two-dimensional atomic crystal size of less than 100 mu m; CVD method of substrate dependent crystal growth can be small, the sample size of more than 100 mu m. In addition, two methods for two-dimensional layered composites with uniform thickness, element distribution, high crystal quality, excellent light induced fluorescence. Van Derwal stack structure the localization of two-dimensional layered materials in MoS2 were observed by Raman spectroscopy and first principle simulation results show the localization of Van de Waal stacking manner will produce axial in the sample Stress, and the stress is estimated at about 0.5% PL peak move proved the localization van Derwal interactions of this material in the optical band gap had obvious effects. This shows that in the thin material MoS2 even without external stress and through the crystal boundary and inter layer Co. the role of the interlayer structure will have a significant impact. A two-dimensional layered modular material accumulation can be controlled based on the localization of the Van Der Waals stack also provides a control method of the intrinsic physical properties of materials, and avoid the external stress the cumbersome and inconvenient. (2) composite materials of graphene like MoS2 MoS2: single by CVD method (1-x Se2x), Mo (1-x) WxS2 composites by liquid phase method, and the one dimensional nanostructures in two-dimensional single-layer structure, the realization of two molybdenum sulfide materials The regulation of structure and characteristics. This paper discusses two types of composite materials based on MoS2, the first is the use of the CVD method by transition metal sulfide mutual doping was prepared by way of alloying layer MoS2 (1-x) Se2x, Mo (1-x) WxS2 material, by controlling the doping ratio of raw materials can be precise control of doping concentration at the same time, we have proved that the Raman spectral method can accurately judge the type of doping elements and doping concentration is estimated. After PL test, we proved that this way can be mixed with Se, the band gap of W alloy single-layer materials from 1.55 eV (MoSe2) to 1.97 eV (WS2) regulation. In order to meet the different requirement. Because the PL peak is very sensitive to the doping concentration, so it can be measured by alloying PL peak amplitude offset reverse calculation of doping concentration. Second is the combination of CVD and hydrothermal method Preparation of molybdenum disulfide / Zinc Oxide nanorod composite structure, that not only can be used as a single-layer Zinc Oxide nanorod growth seed layer, will not lead to lattice distortion of each other, but also can guarantee the trend of Zinc Oxide and Zinc Oxide in the vertical growth of nanorods, in this composite structure to the light focusing effect of antenna, the optical signal at the bottom of MoS2 was increased. Two kinds of material properties of the composite structure of mutual integration, complement each other, is a typical example of two dimensional nano materials and composite materials are one-dimensional improved performance. (3) single-layer slim Van Der Waals heterojunction research: Based on the design and verification of MoTe2/MoS2 II heterojunction two-dimensional monolayer between layers in the infrared the transition, and obtained a 2D heterojunction infrared detection prototype device. Using the self transfer platform was prepared for the first time MoTe2/MoS2 single heterojunction sample, theoretical calculation and KPFM results show that the band combination for the II class configuration, and some literature to predict the consistency, we use the Raman spectra, PL spectra were observed between MoTe2/MoS2 strong interlayer coupling interaction. By using the KPFM test method for the first time in the single MoTe2/MoS2 heterostructure observation to produce and the separation of photogenerated carriers, we confirmed this slim Van Der Waals prepared to achieve heterogeneous electrical function. The light response test prototype devices were prepared by a single MoTe2/MoS2 heterojunction system, the test results show that the MoTe2/MoS2 heterojunction breaking the pure monolayer MoTe2 and MoS2 photoresponse cut-off band, using II band the excitation wavelength of 1550 nm to achieve the same light response. This indicates that the Van Der Waals class II heterojunction atomic layer can be achieved between layers of excitation in optical detection in The value of one step of research.

【學(xué)位授予單位】：中國(guó)科學(xué)院研究生院(上海技術(shù)物理研究所)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類號(hào)】：TQ136.12

【引證文獻(xiàn)】

相關(guān)期刊論文 前1條

1 謝中柱;許并社;樊建鋒;;納米二維材料發(fā)展和應(yīng)用探究[J];信息記錄材料;2016年06期

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本文編號(hào)：1585899