简介:采用超高真空气相沉积系统外延硒(Se)超薄层钝化Si(100)表面,研究其与金属铝(A1)、铂(Pt)的接触特性。对于A1与Se钝化后的Si接触样品,其肖特基势垒高度(SBH)值为0.2eV,相比于HF处理的样品,SBH降低了一半;随着退火温度从200P升至500P,SBH值逐渐升高至HF处理的样品的SBH值。而对Pt与Se钝化的Si接触样品,未退火时电流电压特性基本与HF处理的样品一致,然而快速热退火后,Se钝化的样品基本保持不变,而HF处理的样品反向偏置电流迅速增大。通过拟合金半接触SBH与金属功函数的关系,得到线性关系的斜率为:=0.41,说明硒超薄层可以降低Si(100)表面与金属接触费米钉扎效应。
简介:TheelectronicpropertiesandtopologicalphasesofThXY(X=Pb,Au,Pt,PdandY=Sb,Bi,Sn)compoundsinthepresenceofspin–orbitcoupling,usingdensityfunctionaltheoryareinvestigated.TheThPtSncompoundisstableintheferromagneticphaseandtheotherThXYcompoundsarestableinnonmagneticphases.Bandstructuresofthesecompoundsintopologicalphases(insulatorormetal)andnormalphaseswithingeneralizedgradientapproximation(GGA)andEngel–Voskogeneralizedgradientapproximation(GGAEV)arecompared.TheThPtSn,ThPtBi,ThPtSb,ThPdBi,andThAuBicompoundshavetopologicalphasesandtheotherThXYcompoundshavenormalphases.Bandinversionstrengthsandtopologicalphasesofthesecompoundsatdifferentpressurearestudied.Itisseenthatthebandinversionstrengthsofthesecompoundsaresensitivetopressureandforeachcompoundasecond-orderpolynomialfittedonthebandinversionstrengths–pressurecurves.
简介:UsingvanderWaalscorrecteddensityfunctionaltheory(vdW-DF)methodwehaveinvestigatedtheadsorptionofacetonemoleculeonpristineandPt-dopedgraphene.Severalactivesitesforboththeinteractingsystemshavebeenconsideredintheadsorptionprocessincludingfullgeometryoptimization.Wehaveanalyzedthestructuralandelectricalpropertiesofenergeticallyfavorableconfigurations.TheresultsshowthatadsorptionofacetonemoleculeonthePt-dopedgrapheneisenergeticallypreferable.Thebindingenergyandbondingdistancearedeterminedtobe-5.277eVand2.206A,respectively,accompanyingwithchargetransferof1.11e.Furthermore,thePt-0bondisrathersignificantlyelongatedwhenacetoneisadsorbedonPt-dopedgraphene.Comparedtopristinegraphene,thePt-dopedgraphenehasstrongerinteractionwiththeacetoneandmayprovidemoresensitivesignaiforasingleacetonemolecule.Meanwhile,practically,thebandgapofPt-dopedgraphenewouldbecomereducedafteracetoneadsorption.Consequently,ourfirst-principlesstudypresentsevidenceforacoherentbenchmarkfortheapplicabilityofPt-dopedgrapheneforacetoneadsorptionanddetection.
简介:摘要:随着轨道交通的不断发展,在机车上的Pt100温度传感器具有重要的作用,所以当前应用比较广泛, 因此简要地分析Pt100温度检测电路工作原理,提出了机车调试过程中温度检测,以及电路无法校线检查的具体解决方案, 从而全面地提升了调试水平,并有效地确保了机车的安全稳定运行。