1 Suzhou Talesun-Yue Li

2019 What is next for PERC 2019.06.05 Suzhou Talesun Solar Technologies Co.Ltd. Yue Li Outline Company Profile Technical Background SiO2+Poly: Application Conclusions 表明光滑平整 1、 Company Profile Cell capacity: 4 Gw Module Capacity: 5GW Awards: 50+; Patents: 260+ Production Plants: Four Talesun Cell Module Solar energy systems and solutions 2、 Technical Background Positive charge density: SiOx and SiNx films Parasitic Shunting Negative charge density: Al2O3 film No parasitic shunting Journal of Vacuum Science Energy Procedia 8 (2011) 307–312 ; Al2O3/SiNx stacks (Seff planes; P-tail ECV of P doping profiles of investigated polySi/SiOx/Si structures The presence of an optimised iOx layer: high quality surface passivation Physica Status Solidi (a), 2017:1700058; Energy Procedia 124 (2017) 635–642; Energy Materials and Solar Cells 187 (2018) 76–81 3、 SiO2+Poly: Application Passivated Rear and Front ConTacts (PeRFeCT) Solar Energy Materials and Solar Cells 159 (2017) 265–271; Solar RRL, 2017, 1(7):1700040. SiO2 / Poly-Si on the front side: Parasitic absorption losses about 0.5 mA/cm2 per 10 nm poly-Si layer thickness Passivated Rear and Front ConTacts: SiO2 / Poly-Si formed underneath the front metal grid Current Crowding Current crowding: the highest tunneling probability through the thin SiO2 PeRFeCT : rear junction: ＞ 26% front junction: ～ 24% 3、 SiO2+Poly: Application POLO‐IBC : 26.1% on a 1.3 Ωcm p-type FZ wafer 24.6% on a 2 Ωcm n-type Cz wafer Solar Energy Materials and Solar Cells 186 (2018) 184–193 Progress in Photovoltaics Research and Applications, 2019(1). Polycrystalline Si (poly-Si) on oxide (POLO)junctions- interdigitated back contact (IBC) solar cell POLO-IBC: More complicated fabrication steps beyond the industrial application 3、 SiO2+Poly: Application Tunnel Oxide Passivated Contact (TOPCon) Better passivation: iOx : chemical passivation Heavily-doped poly-Si(n+)layer: field- effect passivation Energy Materials and Solar Cells 187 (2018) 76–81 Schematic drawing of the bifacial n-type solar cell with n-polySi/SiOx contacts N-type Czochralski (Cz) substrate: 1) Higher bulk lifetime : higher open-circuit voltage 2) Unaffected by the light-induced degradation n-type c-Si devices will reach 25% of global PV production by 2027 25.1% efficiency with TOPCon from Fraunhofer ISE 3、 SiO2+Poly:Application Tunnel Oxide Passivated Contact (TOPCon) TOPCon 20-200 nm 2 nm Applied Physics Letters, 2018, 113(6):061603 Progress in Photovoltaics Research 2) Laser edge isolation supplies a positive impact on Rsh, and a negative impact on the Jsc by reducing the current collecting area of the cell; 3) Simultaneous illumination and heating for the permanent deactivation of the boron-oxygen complex ; N-type Si SiO2 SiO2 P doped Poly P doped PolySiN x P-type Si SiO2 SiO2 B doped Poly B doped PolySiN x SiNx (1) Texture+Polish (2) LPCVD:SiO2+Poly (3) P/B doping for N/P Silicon (4) Remove PSG/BSG (5) SiNx SiNx 2.6 fA/cm2 Symmetrical Structure (6) Firing 23.6 fA/cm2 3、 SiO2+Poly:Application N type: 1) 4 Ωcm 2) Cz-Si wafers with 156.75 mm 3) thickness of 180 μm P type: 1) 1 Ωcm 2) Cz-Si wafers with 156.75 mm 3) thickness of 180 μm Our work 3、 SiO2+Poly:Application Our work I-V parameters Isc Jsc Uoc FF Eta Rs Rsh IRev2 TOPCon solar cell 9.538 39.040 0.635 78.58 19.49 0.0072 11.82 6.43 P-type MONO PERC 9.806 40.13 0.668 80.77 21.64 0.0021 719.13 0.08 The front side of TOPCon solar cell based on P-type silicon J0=557 fA/cm2 J0=252 fA/cm2 4、 Conclusions 1) The surface recombination strongly influence the solar cell performance; 2) SiO2 / Poly-Si for carrier selective with different c-Si devices can provide better passivation via chemical passivation and field-effect passivation; 3) SiO2 / Poly-Si for carrier selective can reach the limiting efficiency. Thanks for your attention! 苏州腾晖光伏技术有限公司致力于成为 全球领先的产品 设计、研发、制造、应 用 一体化的方案提供商