新能源材料新能源材料太阳能电池材料太阳能电池材料北航材料学院于荣海太阳能电池材料材料类型材料转化效率%硅多晶9-12非晶(膜)6-9单晶~20化合物半导体GaAs(晶)18-30CdS,CdTe(膜)10-12CuInSe2(膜)10-12敏化纳米染料薄膜(大面积)5有机太阳能转换膜<5GlobalCarbonDioxideEmissionsGlobalCarbonDioxideEmissionsGlobalCO2emissionsfromfossilfuelburning,cementproduction,andgasflaringfor1751-1999Whilegrossdomesticproduct(GDP)grewby38percentfrom1990to2000,energy-relatedcarbondioxideemissionsgrewby16percent.GDPGrowthandCarbonDioxideEmissions开发新能源开发新能源太阳能:辐射于地面的太阳能1万倍于目前人类所需能源,取之不尽,用之不竭。但密度低(1kw/m2),受地域和气候影响大。太阳能可分为光伏能和太阳炉,光电转换效率不高!太阳能热水器太阳能汽车FUNCTIONOFTHESOLARFUNCTIONOFTHESOLARCELLCELL......SolarCellLoadICONVERTSLIGHTLIGHTINTOELECTRICELECTRICCURRENTCURRENTUVIRVisible01x10212x10213x10214x10210.511.522.533.54PhotonEnergy(eV)2/sec/eV0.4m2.0m0.7m1.0mc-Sic-Sic-Genc-GeSolarSpectrumSolarSpectrumPhotons/mEnergyBandStructuresandConductivitySemiconductorsandInsulatorsMetalsSiliconDopingSiliconDopingSi(4valenceelectrons)P(5valenceelectrons)Forn-typen-typedopingResultsinextraelectronsB(3valenceelectrons)Forp-typep-typedopingResultsinextraholesee--hh++TheThePINStructurePINStructureN-layerN-layerP-layerP-layerI-layerI-layerContainspositivemobilechargecarriersContainsnegativemobilechargecarriersStaticElectricField----++++Fixeddopantions半导体光伏效应原理PN++++----++++-----e+h阳光NP-e+h+-半导体P/N结太阳光照在半导体p-n结上,形成新的空穴-电子对,在p-n结电场的作用下,空穴由n区流向p区,电子由p区流向n区,接通电路后就形成电流。这就是光电效应太阳能电池的工作原理。SolarPower:NotCheapEnoughSolarPower:NotCheapEnoughSoonEnough!SoonEnough!Solarpowerneedstobe10-100timescheapertobecompetitiveEvenrelativelylow-techwindpowerhastaken20yearstodecreaseincostby85%光电转换效率低最近美国加州大学开发出多波段半导体光电转换材料,其转换率高达37%...硅材料制备1.多晶硅定向凝固单晶硅非晶硅FilmFilmGrowthGrowth::PlasmaE...