中德PV會議(英利新能源)太陽能光伏專用資料很有用的 課件

1、Advanced Hybrid Silicon Solar Cells Dr. Guoxiao Yao CTO of Tianwei Yingli New Energy Resources Co. 姚國曉博士 首席技術(shù)官 中國天威英利新能源有限公司 2019年5月10日2019 SNEC International Solar & PV ConferenceFeatures of Metallization for Screen Printing Silicon Solar CellsFeatures of Metallization for Buried Contact Silicon So

2、lar CellsFeatures of Metallization for Hybrid Silicon Solar CellsProcessing Technology of Metal StencilsLaser-Processed Single-Level & Double-Level Stainless Steel StencilPerformance of Hybrid Silicon Solar Cells ConclusionsContentsAdvantages:Good availability of screen printing machine & firing fur

3、nace in the market;Simplicity of processing sequence.Disadvantages:Relatively wider finger width (150 um), leading to higher shading loss (10%);Relatively lower height-to-width aspect ratio (0.06), leading to higher resistive loss, lower FF. Lower opening percentage (40%) of screen & gradual degrada

4、tion of printing lines with the wear and tear of the emulsion layer. Features of Metallization for Screen Printing Solar Cellsrear metal contact2-3 mm150 umFigure 1: The structure of screenprinting solar cellsAdvantages:Very fine top finger width (25 um), leading to lower shading loss (3%);Pretty hi

5、gh height-to-width aspect ratio (as high as 5), leading to lower resistive losses, higher FF; Lower contact resistance, further reducing the resistive loses, increasing FF.Disadvantages:Much longer metallization process;Consuming more wet chemicals, less environmentally friendly.Figure 2: The struct

6、ure of buried contact solar cells25 umFeatures of Metallization for Buried Contact Solar CellsFigure 3: Schematic of a hybrid silicon solar cell structureSP Ag contactp-typeP+n+n+oxideSP Al contact50 umA hybrid solar cell incorporates some of the advantages of buried contact and screen printing tech

7、nologiesAdvantages:Relatively fine top finger width (50 um), leading to lower shading loss (6%);Relatively high height-to-width aspect ratio (0.5), leading to lower resistive losses, higher FF; Simplicity of processing sequence.Disadvantages:Mask manufacturing process complicated & costly; Features

8、of Metallization for Hybrid Solar CellsMask fabricationPattern alignmentKey TechniquesAperture Profile:Cell sideSqueegee side40 mFoilLaserGaussian beam profile:Metal Stencil FabricationAperture Profile:40 m35 m40 mCell sideSqueegee sideFoilLaserGaussian beam profile:Aids paste transfer!Metal Stencil

9、 FabricationFinished stencilLocal structureFingerStainless Steel Foil Busbar bridgeBusbarSingle-Level Stainless Steel Stencila stencil-printed finger & busbar68 m (W) x 24 m (H) finger profileProfile of Printed LinesDouble-levelBusbar bridgeDouble-levelBridges betweenFinger & busbarDouble-levelFinge

10、r bridgeFirst Level = Wire Mesh of a Conventional ScreenSecond Level = Wire Mesh +EmulsionBottom ViewSide ViewDouble-Level Stainless Steel StencilPrinted FingerPrinted BusbarSingle-LevelStencil PrintingDouble-LevelStencil PrintingPrinting Comparison Figure 25: (a) The grooves just after laser scribi

11、ng shows some islands; (b) the clean grooves after laser scribing and chemical etching.Oxide0.014Single scribingIsland1.67(a)OxideFormed wider groove0.050.026 1.670.05(b)Features & Formation of the Grooves1. Print a test pattern on a dummy waferWafer nestStencilAlignment2. Indicate 8 alignment point

12、s using the laser vision systemPut a pic about laser boxAlignment3. Calculate the translation and rotation with respect to the print nestrAlignment4. Translate and rotate the groove scribe pattern using softwarer, Alignment5. Laser scriber now registered to the stencil print nestr, Alignment6. Proce

13、ed to cut grooves on process wafersWafer nest7. The stencil is pre-aligned to print directly into the groovesAlignmentFinger Profile:50 m wide & 22 m highBusbar Profile:230 m wide & 22 m highStencil Printed Finger & Busbar Cell Results & Best Cell I-V Curve15.80.7633.76194245Average16.40.7734.262542

14、45Best cell (%)FF (%)Jsc (mA/cm2)Voc (mV)Area (cm2)W (m)Cell name 0.005.0010.0015.0020.0025.0030.0035.0040.000.000.100.200.300.400.500.600.70Voltage (V)Current Density (mA/cm2)Cell Results & Best Cell I-V Curve15.80.7633.76194245Average16.40.7734.26254245Best cell (%)FF (%)Jsc (mA/cm2)Voc (mV)Area (

15、cm2)W (m)Cell name 0.005.0010.0015.0020.0025.0030.0035.0040.000.000.100.200.300.400.500.600.70Voltage (V)Current Density (mA/cm2)Quantum Efficiency of the Best Cell Laser cutting and chemical etching suitable for stencil fabricationBoth single- & double-level structured stencils have been fabricated. Double-level stencils allow grid patterns to be printed with high quality in one step.Finger profiles of 50-m wide and 22-m high, in grooves, have been demonstratedA novel alignment method enables