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1、内容：内容：qq黑体辐射与能量量子化的假设黑体辐射与能量量子化的假设黑体辐射与能量量子化的假设黑体辐射与能量量子化的假设qq光电效应光电效应光电效应光电效应qq康普顿效应康普顿效应康普顿效应康普顿效应 qq氢原子光谱与玻尔的氢原子理论氢原子光谱与玻尔的氢原子理论氢原子光谱与玻尔的氢原子理论氢原子光谱与玻尔的氢原子理论qq微观粒子的波粒二象性微观粒子的波粒二象性微观粒子的波粒二象性微观粒子的波粒二象性qq测不准关系测不准关系测不准关系测不准关系qq薛定鄂方程薛定鄂方程薛定鄂方程薛定鄂方程qq无限深势阱中的粒子无限深势阱中的粒子无限深势阱中的粒子无限深势阱中的粒子qq激光原理激光原理激光原理激光原
2、理qq晶体点阵及电子波在周期势场中的传播晶体点阵及电子波在周期势场中的传播晶体点阵及电子波在周期势场中的传播晶体点阵及电子波在周期势场中的传播应用应用Lect半导体电子Atoms（原子核）（原子核）（外层电子、价带电子）（外层电子、价带电子）（激发态电子）（激发态电子）Lect半导体电子More than One Atom（价带层）（价带层）（共价键（共价键 键合）键合）（离子键（离子键 键合）键合）Lect半导体电子Solids have Quantized Energy Levels（禁带）（禁带）（允带）（允带）（原子间距）（原子间距）Lect半导体电子2s BandOverlappin
3、g energybandsElectrons2s2p3s3p1s1sSOLIDATOME = 0Free electronElectron Energy, E2p Band3s BandVacuumlevelConductor (metals)Li（真空（真空能级）能级）（自由电子）（自由电子）（导体、金属）（导体、金属）Lect半导体电子Semiconductors(a) A simplified two dimensional view of a region of the Si crystalshowing covalent bonds. (b) The energy band diag
4、ram of electrons in theSi crystal at absolute zero of temperature.Electron energy, EConduction Band(CB), Empty of electrons at 0 K.EcEv0Ec+c(b)Band gap = Eg(a)Covalent bondSi ion core (+4e)Valence Band(VB), Full of electrons at 0 K.（半导体）（半导体）（电子亲和能）（电子亲和能）（导带）（导带）（价带）（价带）（能带结构图）（能带结构图）（Si：硅Silicon）L
5、ect半导体电子Electrons in periodic energy potential fieldSchrdinger equation:（薛定谔方程薛定谔方程）PE of the electron around an isolated atomrPE(r)xV(x) x=Lx=0a2a3a0aaSurfaceSurfaceCrystalWhen N atoms are arranged to form the crystal then there is an overlap of individual electron PE functions.PE of the electron,
6、V(x), inside the crystal is periodic with a period a.（周期能势场中的电子）（周期能势场中的电子）Lect半导体电子E-K Diagram :Ekk-p/aEcEvThe E-k DiagramEmpty ykh+e-EghvValenceBand (VB)p/aConductioinBand (CB)Occupied yk（能带结构图，即能量电子波矢关系）（导带）（导带）（价带）（价带）EcEvC BThe Energy BandDiagrame -h+hvV B（导带）（导带）（价带）（价带）e: 电子 electronh: 空穴 hol
7、eLect半导体电子n-type Silicone-As+The As atom donates an electron into the CB, thus it is called a donor impurity.p-type SiliconB-h+The B atom accepts an electron from the CB, thus it is called a acceptor imipurity.As: 砷B:硼（硅）施主 杂质受主 杂质Lect半导体电子In Intrinsic Semiconductor ( pure, perfect, undoped )=ni int
8、rinsic concentrationIts also true for non-intrinsic (extrinsic, doped) semiconductors !ECEvEFiCBVBIntrinsicFew free carriers本征本征 半导体半导体自由 载流子费米能费米能级级EFLect半导体电子ni vs. TLect半导体电子EcEF - eVABV(x), PE(x)xPE(x) = - eV EElectron EnergyE c - eVEv- eVV(x)EFEvVn-Type SemiconductorEnergy Band Diagramsin an Ap
9、plied Field（外加电压下的能带结构（外加电压下的能带结构Its a non-equilibrium situation.（非平衡情况下）（非平衡情况下）ECEvEFiCBVBIntrinsic本征本征 半导体半导体费米能费米能级级EFLect半导体电子EFpECEvEaEFnECEvEdn-typep-typee majority carrier（多子）（多子）h minority carrier（少子）（少子）h majority carrier（多子）（多子）e minority carrier（少子）（少子）非本征非本征 半导体半导体n-型、p-型ECEvEFiCBVBIntr
10、insicFew free carriers本征本征 半导体半导体自由 载流子费米能费米能级级EFUnder equilibrium:nn0 = Ndpn0 = ni2 / Nd2np0 = ni2 / Na2 pp0 = NaLect半导体电子Carrier Density as function of (N, T)At high temperatures, ni |Nd - Na| ; n, p niThe material becomes intrinsic(载流子密度)Lect半导体电子 n-type As+e-B-h+p-type PN Junction（PN结）结）EvacuumE
11、vEcEFpEcEFnEvnp导带底导带底价带顶价带顶费米能级费米能级WpWnNeutral n-regionNeutral p-regionSpace charge region Eo 空间电荷区（耗尽区）空间电荷区（耗尽区）EcEvEcEFMEFeVoEoEvnpV0 ：自建电压：自建电压Lect半导体电子A. Forward Bias （正向偏置）（正向偏置）pV（外加电压）（外加电压）InEo-Ee(Vo-V)eVEcEFnEvEvEcEFpB. Reverse Bias （反向偏置）（反向偏置）V rnpE cEF nEvEcEF pEve(Vo+Vr )Eo+ELect半导体电子P
12、rinciples of LEDs（Light Emitting Diode，发光二极管）发光二极管）(a)pn+EgeVo Electron in CB（导带） Hole in VB（价带）EcEvEFeVoElectron energyDistance into the deviceEcEvEFSpontaneous emission（自发发射）（自发发射）huEcEvhv EgEg(b)Vpn+e(V0-V)正向偏置正向偏置Lect半导体电子Principles of PN photodetectors（光探测器）（光探测器）EvEchuAbsorption （吸收）p +SiO 2El
13、ectrode（电极）（电极）Re -h+Iphhu E gWEnDepletion region（耗尽区）（耗尽区）(a)AntireflectionCoating（减反膜）（减反膜）VrElectrode（电极）（电极）Vout反向偏置反向偏置Lect半导体电子E1E2huAbsorption（吸收）（吸收）huSpontaneous emission（自发发射）（自发发射）E2E1huStimulated emission（受激发射）（受激发射）InhuOuthuE2E1Three possible processes in photon-electron interactions( hv = E2 - E1 )In stimulated emission, number of photons are amplified.Lect半导体电子Lect半导体电子
