二硫化钼,二维材料性质

1、Few-Layer MoS2: A Promising Layered SemiconductorTHE PREFACEThe single-layer graphene opened up new possibilities and research into the physics of two-dimensional materials. 新技术，仪器的应用： 二维材料制备方法新原子物理理论：原子厚度层级理论新种二维材料：TMDCs（过渡金属硫化物）拓扑绝缘体各种二维材料结构示意图什么是？TMDCs are MX2-type compounds where M is a transiti

2、on element from groups IV, V, and VI of the periodic table and X represents the chalcogen species S, Se, and Te.二硫化钼，二硫化钨、二硫化钛、二硒化钼 The presence of unsaturated d-orbitals contributed by transition metals to the materials band structure introduces a multitude of interesting properties的奇特性质1.charge de

3、nsity waves2.Magnetism3.superconductivity4.band gaps vary with the number of layersMoS2 :因为其在自然中易得性和实用性，是目前TMDCs中研究最广泛的二维材料CONTENDI.Discuss the interesting property of few-layered MoS2 materialsII. Introduce fabrication method of the 2D materials and analyze their advantage and the disadvantageIII.

4、Highlight the current application of few-layered MoS2 materials.I. I.Discuss the interesting property of few-Discuss the interesting property of few-layerd MoS2 materialslayerd MoS2 materials带隙类型随层数变化4lay 3lay 2lay 4lay 3lay 2lay 1lay1layHybridization between p z-orbitals of S atoms and the d-orbita

5、ls of molybdenum atoms and are affected by interlayer interactions. The bands at are more affected by a decrease in layer number随层数减少，MoS2的带隙类型由间接带隙变为直接带隙这使得其在光学探测领域具有潜力I. I.Discuss the interesting property of Discuss the interesting property of few-few-layered layered MoS2 materialsMoS2 materials能带

6、工程垂直电场A vertical electric field exerted to few-layer MoS2 is found to be an efficientmethod for band gap engineering. The band gap of bilayer MoS2 could be be tuned to zero tuned to zero with an electric field of about 1.0-1.5 V/.拉伸应变Band structure redesign under tensile strain is predicted to lower

7、 the electron effective mass and consequently improve electron mobilityII. Introduce II. Introduce fabrication method of the fabrication method of the 2D2D materials materialsExfoliation:“Scotch tape method” Chemical exfoliationExfoliation of MoS2.(a)Optical and(b)AFM height image of multilayer sect

8、ions of a MoS2 flake on a 285nm silicon oxide substrate.II. Introduce fabrication method of the 2DII. Introduce fabrication method of the 2D materials materialsExfoliation:“Scotch tape method” Chemical exfoliationIllustration of controlled lithiation and Subsequent exfoliation using an electrochemic

9、al setupFor example For example : ion : ion intercalationintercalationThe ion intercalation method uses the concept of ion insertion in the gaps between the MoS2 layers, widening the layer gaps缺点是采用的电化学方法，可能会改变材料的性质（2H态和1T态），对于反应条件的要求比较苛刻For example : precursor consisted For example : precursor cons

10、isted of thin of thin layer of layer of molybdenummolybdenum在衬底（此处是蓝宝石）上蒸镀一层单质Mo，然后在高温（1000C）硫氛围下进行硫化反应产物性质产物性质grain sizes：10-30nm，field-effect mobility between 10 and 14 cm2/Vs相对于物理剥离法，仍有较大差距（ Mob ：400cm2/Vs）Growth:Grown from precursorsGrown by CVDII. Introduce fabrication method of the 2DII. Intro

11、duce fabrication method of the 2D materials materialsIII. Highlight the current application of few-layered MoS2 materials.少层二硫化钼因其出众的物理和电学性质，已经在场效应管，异质结器件，电路器件，光电器件，传感器等领域都有报道。MoS2和石墨烯的异质结结构制成的快闪存储单元，利用了石墨烯的高电子迁移率和MoS2有带隙的特点，其存储电荷能够保存30%在十年内。采用High-k电介质材料，高质量衬底制备出高电子迁移率的FET器件200 to 400 cm2/VsIII. Hi

12、ghlight the current application of few-layered MoS2 materials.The direct transition optical gap in few-layer MoS2 opens the doors to interesting optoelectronic applications. The very first MoS2 optoelectronic device was reported by Yin et al. The device was a phototransistor fabricated on monolayer

13、MoS2几种单层MoS2材料制成的光电探测器APPLICATIONWhile huge research interests are focused on 2D MoS2 sheets, other nanostructures like MoS2 nanotubes and Nano ribbons have received attention for their confinement-induced physics and properties.NanoribbonsNanoribbons（纳米带）：MoS2 nanoribbons are basically very thin nanosized strips having widths much smaller than their lengthsNanotu