Few-LayerMoS2:APromising

LayeredSemiconductor

2021/5/91THEPREFACEThesingle-layergrapheneopenedupnewpossibilitiesandresearchintothephysicsoftwo-dimensionalmaterials.新技術(shù)，儀器的應(yīng)用：

二維材料制備方法新原子物理理論：原子厚度層級理論新種二維材料：TMDCs（過渡金屬硫化物）拓?fù)浣^緣體各種二維材料結(jié)構(gòu)示意圖2021/5/92什么是TMDCs？TMDCsareMX2-typecompoundswhereMisatransitionelementfromgroupsIV,V,andVIoftheperiodictableandXrepresentsthechalcogenspeciesS,Se,andTe.

二硫化鉬，二硫化鎢、二硫化鈦、二硒化鉬

2021/5/93Thepresenceofunsaturatedd-orbitalscontributedbytransitionmetalstothematerial'sbandstructureintroducesamultitudeofinterestingpropertiesTMDCs的奇特性質(zhì)chargedensitywavesMagnetismsuperconductivitybandgapsvarywiththenumberoflayersMoS2:因為其在自然中易得性和實用性，是目前TMDCs中研究最廣泛的二維材料2021/5/94CONTENDDiscusstheinterestingpropertyoffew-layeredMoS2materialsIntroducefabricationmethodofthe2DmaterialsandanalyzetheiradvantageandthedisadvantageHighlightthecurrentapplicationoffew-layeredMoS2materials.2021/5/95Discusstheinterestingpropertyoffew-layerdMoS2materials

帶隙類型隨層數(shù)變化4lay3lay2lay1layHybridizationbetweenpz-orbitalsofSatomsandthed-orbitalsofmolybdenumatomsandareaffectedbyinterlayerinteractions.ThebandsatΓaremoreaffectedbyadecreaseinlayernumber隨層數(shù)減少，MoS2的帶隙類型由間接帶隙變?yōu)橹苯訋哆@使得其在光學(xué)探測領(lǐng)域具有潛力2021/5/96Discusstheinterestingpropertyoffew-layeredMoS2materials

能帶工程垂直電場Averticalelectricfieldexertedtofew-layerMoS2isfoundtobeanefficientmethodforbandgapengineering.ThebandgapofbilayerMoS2couldbetunedtozerowithanelectricfieldofabout1.0-1.5V/?.拉伸應(yīng)變Bandstructureredesignundertensilestrainispredictedtolowertheelectroneffectivemassandconsequentlyimproveelectronmobility2021/5/97II.Introducefabricationmethodofthe2D

materialsExfoliation:“Scotchtapemethod”ChemicalexfoliationExfoliationofMoS2.(a)Opticaland(b)AFMheightimageofmultilayersectionsofaMoS2?akeona285nmsiliconoxidesubstrate.2021/5/98II.Introducefabricationmethodofthe2D

materialsExfoliation:“Scotchtapemethod”ChemicalexfoliationIllustrationofcontrolledlithiationandSubsequentexfoliationusinganelectrochemicalsetupForexample:ionintercalationTheionintercalationmethodusestheconceptofioninsertioninthegapsbetweentheMoS2layers,wideningthelayergaps缺點是采用的電化學(xué)方法，可能會改變材料的性質(zhì)（2H態(tài)和1T態(tài)），對于反應(yīng)條件的要求比較苛刻2021/5/99Forexample:precursorconsistedofthinlayerofmolybdenum在襯底（此處是藍寶石）上蒸鍍一層單質(zhì)Mo，然后在高溫（~1000°C）硫氛圍下進行硫化反應(yīng)產(chǎn)物性質(zhì)grainsizes：10-30nm，field-effectmobilitybetween10and14cm2/Vs相對于物理剝離法，仍有較大差距（Mob：400cm2/Vs）Growth:GrownfromprecursorsGrownbyCVDII.Introducefabricationmethodofthe2D

materials2021/5/910III.Highlightthecurrentapplicationof

few-layeredMoS2materials.少層二硫化鉬因其出眾的物理和電學(xué)性質(zhì)，已經(jīng)在場效應(yīng)管，異質(zhì)結(jié)器件，電路器件，光電器件，傳感器等領(lǐng)域都有報道。MoS2和石墨烯的異質(zhì)結(jié)結(jié)構(gòu)制成的快閃存儲單元，利用了石墨烯的高電子遷移率和MoS2有帶隙的特點，其存儲電荷能夠保存30%在十年內(nèi)。采用High-k電介質(zhì)材料，高質(zhì)量襯底制備出高電子遷移率的FET器件200to～400cm2/Vs2021/5/911III.Highlightthecurrentapplicationof

few-layeredMoS2materials.Thedirecttransitionopticalgapinfew-layerMoS2opensthedoorstointerestingoptoelectroni