《Lect半导体电子》PPT课件

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1、内容：黑体辐射与能量量子化的假设光电效应康普顿效应氢原子光谱与玻尔的氢原子理论微观粒子的波粒二象性测不准关系薛定鄂方程无限深势阱中的粒子激光原理晶体点阵及电子波在周期势场中的传播应用Atoms（原子核）（外层电子、价带电子）（激发态电子）MorethanOneAtom（价带层）（共价键键合）（离子键键合）SolidshaveQuantizedEnergyLevels（禁带）（允带）（原子间距）2sBandOverlappingenergybandsElectrons2s2p3s3p1s1sSOLIDATOME=0Free

2、electronElectronEnergy,E2pBand3sBandVacuumlevelConductor(metals)Li（真空能级）（自由电子）（导体、金属）Semiconductors(a)AsimplifiedtwodimensionalviewofaregionoftheSicrystalshowingcovalentbonds.(b)TheenergybanddiagramofelectronsintheSicrystalatabsolutezerooftemperature.Electronener

3、gy,EConductionBand(CB),Emptyofelectronsat0K.EcEv0Ec+c(b)Bandgap=Eg(a)CovalentbondSiioncore(+4e)ValenceBand(VB),Fullofelectronsat0K.（半导体）（电子亲和能）（导带）（价带）（能带结构图）（Si：硅Silicon）ElectronsinperiodicenergypotentialfieldSchrödingerequation:（薛定谔方程）PEoftheelectronaroundaniso

4、latedatomrPE(r)xV(x)x=Lx=0a2a3a0aaSurfaceSurfaceCrystalWhenNatomsarearrangedtoformthecrystalthenthereisanoverlapofindividualelectronPEfunctions.PEoftheelectron,V(x),insidethecrystalisperiodicwithaperioda.（周期能势场中的电子）E-KDiagram:Ekk-p/aEcEvTheE-kDiagramEmptyykh+e-Eg

5、hvValenceBand(VB)p/aConductioinBand(CB)Occupiedyk（能带结构图，即能量～电子波矢关系）（导带）（价带）EcEvCBTheEnergyBandDiagrame-h+hvVB（导带）（价带）e:电子electronh:空穴holen-typeSilicone-As+TheAsatomdonatesanelectronintotheCB,thusitiscalledadonorimpurity.p-typeSiliconB-h+TheBatomacceptsanelectronf

6、romtheCB,thusitiscalledaacceptorimipurity.As:砷B:硼（硅）施主杂质受主杂质InIntrinsicSemiconductor(pure,perfect,undoped)==ni—intrinsicconcentrationIt’salsotruefornon-intrinsic(extrinsic,doped)semiconductors!ECEvEFiCBVBIntrinsicFewfreecarriers本征半导体自由载流子费米能级EFnivs.TEcEF-eVABV(x)

7、,PE(x)xPE(x)=-eVEElectronEnergyEc-eVEv-eVV(x)EFEvVn-TypeSemiconductorEnergyBandDiagramsinanAppliedField（外加电压下的能带结构It’sanon-equilibriumsituation.（非平衡情况下）ECEvEFiCBVBIntrinsic本征半导体费米能级EFEFpECEvEaEFnECEvEdn-typep-typee–majoritycarrier（多子）h–minoritycarrier（少子）h–majori

8、tycarrier（多子）e–minoritycarrier（少子）非本征半导体n-型、p-型ECEvEFiCBVBIntrinsicFewfreecarriers本征半导体自由载流子费米能级EFUnderequilibrium:nn0=Ndpn0=ni2/Nd2np0=ni2/Na2pp0=NaCarrierDen