高效n双面电池工业技术研究

1、N型晶硅电池及高效组件2016高效N-PERT双面电池工业技术研究Investigation on High Efficiency N-PERT Bifacial Solar Cell张 伟博士Dr. WEI ZHANG英利能源（中国）光伏材料与技术Yingli Energy (China) Co.,State Key Laboratory of Photovoltaic Materials and TechnologyOutlineN-PERT Cell1PANDAN-PERT Cell23N-PERT SBSF Cell4PANDA Module5Summary2N-PERT CellIn

2、dustrial passivated emitter and rear, totally-diffused3PANDA N-PERT CellTexturelB and P diffused regions made by different technologies (two diffusions, co-diffusion using doped glasses, ion implantation with anneal)Most of existing P-type Si process technology can be usedDiffusion /Ion Implantation

3、lEdge IsolationSiN Passivation /ARC Coating PassivationSP Al / AgPassivationDrying & Firing4PANDA N-PERT CellIncident lightTextured front surface with antireflection coatingFront contactFront sideBoron diffused emitter (P+)Phosphorus diffused BSFSiNx passivation coatingRear sideRear contact (Ag)Inci

4、dent lightmass production5l Cost-effective production steps and compatible with existing production linesl Simple cell structure andeasy manufacturel Sun-light can be accepted by double sides, produce more electricityCZ N-Si SubstratePANDA N-PERT CellConventional POCl3 diffusionPhosphorus ion implan

5、tationFront contact(Ag/Al)ARC:SiO2/SiNxFront contact (Ag/Al)ARC :SiO 2/SiNxBact contact (Ag )ARC:SiO2/SiNxEdge isolationARC:SiO2/SiNxBact contact(Ag)6l Even doping surfacel Low rear surface recombinationl Less process steps(P+) emitterN-type SubstrateN+ BSF(P+) emitterN-type Substrate N+ BSFPANDA N-

6、PERT CellEfficiency gain for BSF by ion implantationP diffusionP implantation0.300.280.260.240.220.200.180.160.140.120.100.080.060.040.020.00lImproved cell performance with0.5% efficiency gainNarrower efficiency distributionlbasedcontrolonpreciselydoping19.520.020.521.021.5Cell efficiency(%)7Normali

7、zed countsBSF FormationVoc (mV)Jsc (mA/cm2)FF (%)Eff (%)P Diffusion653.138.7980.9320.50Ion Implantation655.739.5880.8320.98PANDA N-PERT CellIQE and rear efficiency improvements1.020.019.50.819.00.618.5P implantationP diffusion18.00.4P implantation17.5P diffusion0.217.016.50.016.0400600800100012007.6

8、7.88.08.28.4Isc(A)8.68.89.09.2Wavelength (nm)8IQERear side efficiency(%)l IQE improved in the long wavelength regionl Rear efficiency increased due to current improvement, bifacialmodule will be benefit from high rear efficiencyN-PERT SBSF CellSelective back surface field (SBSF)Conventional back sur

9、face fieldFront contact(Ag/Al)ARC:SiO2/SiNxFront contact(Ag/Al)ARC:SiO2/SiNxARC:SiO2/SiNxBack contact(Ag)ARC:SiO2/SiNxBack contact(Ag)9l Low contactl Low back surface recombinationvelocityl Low contactl High back surface recombinationvelocity(P+) emitterN-type SubstrateN+ BSFn+n+n+(P+) emitterN-type

10、 SubstrateN+ BSFN-PERT SBSF CellpandaSBSF CellN-type waferMask printingTexturePhosphous diffusionPSG RemovalBoron diffusionWet chemical etchBSG Removal&IsolationMask PrintingWet chemical etchMask RemovalMask removalPassivation&ARC coatingMlization10(P+) emitterN-type SubstrateN+ BSFn+n+(P+) emitterN

11、-type SubstrateN+ BSFn+n+(P+) emitterN-type SubstrateN+ BSFN-PERT SBSF CellDepthMask WidthBSF passivationAlignmentVocJscFFMask widthDepthVocJscFFEfficiencyEfficiency11(P+) emitterN-type SubstrateN+ BSFn+n+N-PERT SBSF Cell1E21240220200180160140120100806040200POCl3 diffusion 40/sq POCl3 diffusion 16/s

12、q1E201E19POCl3 diffusion 40/sq POCl3 diffusion 16/sq1E181E171E161E150.00.10.20.30.40.50.60.70.80.91.0012345678910Depth(um)Etch time(min)BSF doping profileSheetVs. etching time12surface phosphours concentration(atoms/cm3)Rsh(/sq)l Thermal treatment has great impact not only on the Rsheet but also on

13、the doping profliel Increasing rate of Rsheet is related to the doping profileN-PERT SBSF CellBSF-1BSF-2N-PERT SBSF Cell81.020.566439.0FFEff66220.438.880.566020.338.665880.0656Voc Jsc20.238.465479.520.138.265279.020.065038.010203040506070801020304050607080Rsh(/sq)Rsh(/sq)Cell parameters Vs. Rsheet14

14、Voc(mV)Jsc(mA/cm2)FF(%)Efficiency(%)Suitable etching depth has to be selected for balancing the Voc, Jscand FF that have great effect on the final cell efficiencyN-PERT SBSF CellEtch backMization15GroupMask width(um)Voc(mV)Jsc(mA/cm2)FF(%)Eff(%)G130065739.1779.9320.57G225065939.2179.8620.64G32006613

15、9.2679.8520.71G415066039.3079.8220.68N-PERT SBSF CellSame mask area for G2 and G316GroupMaskfingersMaskwidth(um)Voc(mV)Jsc(mA/cm2)FF(%)Eff(%)G1N-panda65338.8580.4320.40G210820066239.3579.5420.72G3.3180.1220.83N-PERT SBSF Cell1.00.80.6Panda Cell SBSF Cell0.40.20.0400500600700800900100011001200Wavelen

16、gth(nm)17IQEl Better IQE in wavelength of 950-1200nml Improvement of Voc and Jscl Efficiency gain of 0.43%GroupVoc (mV)Jsc (mA/cm2)FF (%)Eff (%)Panda Cell65338.7980.9320.50SBSF Cell66139.4480.2320.93N-PERT SBSF Cell* Tested in calibration lab: National Physical and Chemical Power Products Testing Ce

17、nter18SideArea(cm2)Voc (mV)Jsc(mA/cm2)FF(%)Eff(%)Front242.1661.239.4380.9021.08Rear242.1658.434.6380.8018.41RearFrontPANDA ModuleLID characteristicsAVE. LID = 0.00 %19Excellent anit-LID performancePANDA ModulePower gain under different reflective conditionsGrasslandSand/Gray CementBrightRooftopSnow

18、Field20l 10% power output gain at the ground and grassland with reflectivity of 25%l 15% power output gain at the Sand/gray cement floor with reflectivity of 50%l 25% power output gain at the bright rooftop with reflectivity of 78%l 30% power output gain at the snowfield with reflectivity of 90%PANDA ModulePower output21STC power outputincreased 5%10%15%20%25%30%280 W294 W308 W322 W336 W350 W364 Wl Power output collection for 1 year with installed modules on a bright rooftopl The distance from module to the ground of 30 cml The test result