穿隧型异质接面矽晶太阳电池技术简介-2017年9月

材料世界網 https://www.materialsnet.com.tw 123 工業材料雜誌 369期 2017/09 太陽光電技術 特別報導 穿隧型異質接面矽晶太陽電池技術簡介 The Technology of Tunneling Heterojunction Silicon Solar Cell In recent years, the progress of the green energy industry has become more prosperous due to the growth of the issue of global warming and the environmental consciousness. Solar cell is the main stream of the green energy industry. The priority targets of technology research of the solar cell are high efficiency and low cost. The focus of novel high efficiency solar cell is the tunneling heterojunction solar cell. The simple structure of the tunneling heterojunction solar cell is a passivated contact. The structure combines the advantages of the heterojunction a-Si:H/ c-Si structure, i.e. excellent surface passivation and carrier selectivity. And the structure with a tunneling oxide and a classical poly-crystalline silicon contact has higher temperature stability. In this paper, the technology developments of the tunneling heterojunction silicon solar cell will be introduced. /Key Words (Passivated Contact)(Poly-crystalline Silicon)(T unneling Oxide) 蕭睿中 J. C. Hsiao 1 、林昭正 C. C. Lin 2 、葉峻銘 C. M. Y eh 2 、 杜政勳 C. H. Du 3 工研院綠能所(GEL/ITRI) 1 研究員、 2 資深研究員、 3 正研究員/經理 前 言 P N P (Back Surface Field; BSF) (Passivated Emitter and Rear Cell; PERC) 19~20% (1) 124 材料世界網 https://www.materialsnet.com.tw 工業材料雜誌 369期 2017/09 太陽光電技術 特別報導 21% N (Hetero- junction with Intrinsic Thin Layer; HIT) (2) (Interdigitated Back Contact Solar Cells; IBC) (3) N 23% 圖 一 N N 穿隧型異質接面太陽電池技術 發展介紹 - - - 圖 二 BSF PRC(Partial Rear Contact) IBC 圖 二 BSF PRC PRC Back Contact Cells N-type mono-Si Silicon Heterojunction(SHJ) Cells N-type mono-Si PERC, PERT or PERL Cells N-type mono-Si PERC/PERT Cells P-type mono-Si PERC/PERT Cells P-type mc-Si BSF Cells P-type mono-Si BSF Cells P-type mc-Si Stabilized Cell Efficiency (%) 27 26 25 24 23 22 21 20 19 18 17 2016 2017 2019 2021 Year 2024 2027 PERC ITRPV (2017) ▲圖一 矽晶太陽電池效率發展趨勢材料世界網 https://www.materialsnet.com.tw 125 工業材料雜誌 369期 2017/09 太陽光電技術 特別報導 - - BSF PRC IBC ▲圖二 不 同 太 陽 電 池 結 構 的 電 流 傳 輸 方 式 示 意 圖 (4) Crystalline Si Substrate Protection Layer for Light Receiving Surface Passivation Layer for Light Receiving Surface I-type Amorphous Si (a-Si) P-type a-Si/N-type a-Si Pattern Electrode Pattern Kaneka Corporation (2017) ▲圖三 異質接面太陽電池結構示意圖 (Passivated Emitter with Rear Locally Dif- fused; PERL) (5) (Passivated Contacts) Kaneka (6) 26.6% 圖 三 (a-Si:H) (Interface State Density) (7) 126 材料世界網 https://www.materialsnet.com.tw 工業材料雜誌 369期 2017/09 太陽光電技術 特別報導 (Tunneling Heterojunction Solar Cell) 圖 四 (Tunnel- ing Oxide) (Poly-crys- talline Silicon) (TCO) N Fraunhofer Institute for Solar Energy Systems(ISE) (4,9) Institute for Solar Energy Research Hamelin(ISFH) (10) National Renew- able Energy Laboratory(NREL) (11) Fraun- hofer ISE 圖 五 1 Ωcm FZ N-type (Boron-diffused) 140 Ω/sq (Al 2 O 3 ) TOPCon(Tunnel Oxide Passivated Contact)Fraunhofer ISE TOPCon 25.1%718 mV ISFH 圖 六 (Bifacial Solar Cell) n + Poly-Si n-Si Base Tunnel Oxide Electron E c E v E fn E fp Hole ▲圖四 穿隧型異質接面能帶結構示意圖 (8) TOPCon Ag n-Si p ++ p + Al 2O 3 + ARC ▲ 圖 五 Tunnel Oxide Passivated Contact (TOPCon)結構示意圖 (4)材料世界網 https://www.materialsnet.com.tw 127 工業材料雜誌 369期 2017/09 太陽光電技術 特別報導 (LP-CVD) P N (An- nealing) PN 800~1,050 (TCO) Poly-Si on Passivating Interfacial Oxides(POLO) ISFH POLO Junction iV oc (Imply V oc ) 732 mV J 0 12 fA/cm 2 (12) (1~2 nm) (Thermal Oxidation) (SiO 2 ) 表 一 1.7 nm 表 一 N P 圖 七 (Transmission Electron Microscopy; TEM) 圖 七 1.5 nm (Lifetime) 2 ms Legend Base n + c-Si n + poly-Si p + poly-Si SiO x Metal TCO p + c-Si n-Si ▲圖六 Poly-Si on Passivating Interfacial Oxides (POLO)太陽電池結構示意圖 (12)128 材料世界網 https://www.materialsnet.com.tw 工業材料雜誌 369期 2017/09 太陽光電技術 特別報導 Sinton Instruments WCT-120 圖 八 22.5% 結 論 15 ▼表一 多晶矽薄膜以不同製程方法成長的氧化矽層以及分別在平面與金字塔矽晶片上對表面鈍化的影響 (12) Surface Poly-Si Doping Type H Treatment Chemical Oxide (~1.7 nm) Ozone Oxide Thermal Oxide (~1.7 nm) J 0 (fA/cm 2 ) iV oc @1 sun (mv) J 0 (fA/cm 2 ) iV oc @1 sun (mv) J 0 (fA/cm 2 ) iV oc @1 sun (mv) Planar n + FGA 1.5 742 0.5 743 1.1 742 SiN x 0.6 747 0.6 748 0.8 749 Textured n + FGA 29 693 13 715 11 727 SiN x 6 735 4.4 738 3.8 741 Planar p + FGA 8 718 11 712 6 721 SiN x 5 729 5 727 3.8 734 Textured p + FGA 71 669 112 661 54 681 SiN x 40 690 48 684 27 700 N-typeP-type (2017) ▲圖八 穿隧型異質接面太陽電池製作流程圖 Poly-Si Poly-Si Oxide Oxide Substrate Poly-Si Tunnel Oxide c-Si 10 nm (2017) ▲圖七 摻雜型多晶矽薄膜結合氧化矽層結構材料世界網 https://www.materialsnet.com.tw 129 工業材料雜誌 369期 2017/09 太陽光電技術 特別報導 誌 謝 參考文獻 1. T. Dullweber, M. Siebert, B. Veith, C. Kranz, J. Schmidt, R. Brendel, B.F.P. Roos, T. Dippell, A. Schwabedissen, S. Peters, 27 th European Photovol- taic Solar Energy Conference and Exhibition (2011). 2. Ayumu Yano, Satoshi Tohoda, Kenta Matsuyama, Yuya Nakamura, Takeshi Nishiwaki, Kazunori Fujita, Mikio Taguchi, and Eiji Maruyama, 28 th Eu- ropean Photovoltaic Solar Energy Conference and Exhibition (2012). 3. D. D. Smith, P. Cousins, S. Westerberg, R. De Jesu