Honeycomb Carbon A Review of Graphene 石墨烯综述(19)

Figure19.Chemicalvapordepositionofgrapheneontransitionmetalsubstrates.Opticalmicroscopeimageof(a)thenickelcatalystand(b)theresultinggraphene lm.TEMimagesshowthenucleationof(c)one,(d)three,or(e)fourlayersduringthegrowthprocess.(Reprintedwithpermissionfromref41.Copyright2009AmericanChemicalSociety.)

theenergygapobservedbyangle-resolvedphotoemissionspectroscopy(ARPES).122

Thesecondsubstrate-basedmethodischemicalvapordeposition(CVD)ofgrapheneontransitionmetal lms(seeFigure19).GroupsatMITandinKoreapioneeredtheprocess,whichreliesonthecarbon-saturationofatransitionmetaluponexposuretoahydrocarbongasathightemperature.41-43Mostoften,nickel lmsareusedwithmethanegas.Uponcoolingthesubstrate,thesolubilityofcarboninthetransitionmetaldecreasesandathin lmofcarbonisthoughttoprecipitatefromthesurface.

Oneofthemajoradvantagesofsubstrate-basedmethodsforgraphenesynthesisistheirhighcompatibilitywithcurrentCMOStechnology.Intheory,bothepitaxialandCVDtechniqueshavetheprospectofproducingasinglesheetofgrapheneoveranentirewafer,whichmaybethesimplestwaytointegratethenewmaterialintocurrentsemiconductorprocessesanddevices.TheremainingchallengeforepitaxialandCVDmethodsisobtaining necontrolover lm

Figure18.Siliconcarbideisreducedtographeneassiliconsublimesathightemperature.(a)SEMimageshowssmallhexagonalcrystallites.(Reprintedwithpermissionfromref120.Copyright2006Elsevier.)(b)STMimageshowslong-rangeorderandalowdensityofdefects.[ReprintedwithpermissionfromScience(),ref38.Copyright2006AmericanAssociationfortheAdvancementofScience.]

搜索“diyifanwen.net”或“第一范文网”即可找到本站免费阅读全部范文。收藏本站方便下次阅读，第一范文网，提供最新教学研究Honeycomb Carbon A Review of Graphene 石墨烯综述(19)全文阅读和word下载服务。