超薄多晶硅的掺杂、钝化及光伏特性研究

人工晶体学报 ›› 2022, Vol. 51 ›› Issue (3): 434-440.

超薄多晶硅的掺杂、钝化及光伏特性研究

宋志成^1,2, 杨露², 张春福¹, 刘大伟², 倪玉凤², 张婷², 魏凯峰²

1.西安电子科技大学微电子学院,宽禁带半导体材料与器件教育部重点实验室,西安 710071;
2.青海黄河上游水电开发有限责任公司西安太阳能电力分公司,西安 710000

收稿日期:2021-12-16 出版日期:2022-03-15 发布日期:2022-04-11
通讯作者: 杨露。E-mail:yanglu2468@mail.nwpu.edu.cn
作者简介:宋志成(1985—),男,湖北省人,硕士研究生。E-mail:songzhicheng@spic.com.cn

Doping, Passivation and Photovoltaic Properties of Ultra-Thin Poly-Silicon

SONG Zhicheng^1,2, YANG Lu², ZHANG Chunfu¹, LIU Dawei², NI Yufeng², ZHANG Ting², WEI Kaifeng²

1. Key Laboratory of Wide Bandgap Semiconductor Materials and Devices, Ministry of Education, School of Microelectronics, Xidian University, Xi’an 710071, China;
2. Xi’an Solar Power Branch of Qinghai Huanghe Hydropower Development Co., Ltd., Xi’an 710000, China

Received:2021-12-16 Online:2022-03-15 Published:2022-04-11

摘要/Abstract

摘要： 本文对70 nm超薄多晶硅的掺杂工艺、钝化性能及光伏特性进行了研究。确定了70 nm超薄多晶硅的掺杂工艺,研究表明当离子注入剂量为3.2×10¹⁵ cm^-3,在855 ℃退火20 min时,70 nm超薄多晶硅的钝化性能可以达到与常规120 nm多晶硅相当的水平,且70 nm多晶硅的表面掺杂浓度达到5.6×10²⁰ atoms/cm³,远高于120 nm掺杂多晶硅的表面掺杂浓度(2.5×10²⁰ atoms/cm³)。基于70 nm超薄多晶硅厚度减薄和高表面浓度掺杂的特点,较低的寄生吸收和强场钝化效应使得在大尺寸(6英寸)直拉单晶硅片上加工的N型TOPCon太阳能电池的光电转换效率得到明显提升,主要电性能参数表现为:电流I_sc升高20 mA,串联电阻R_s降低,填充因子FF增加0.3%,光电转换效率升高0.13%。

关键词: TOPCon太阳能电池, 多晶硅, 掺杂, 离子注入, 钝化接触, 寄生吸收, 光电转换效率

Abstract: The doping process, passivation and photovoltaic properties of 70 nm ultra-thin poly-silicon were studied in this paper. The optimal doping process for 70 nm ultra-thin poly-silicon was identified, the results show that when the ion implantation dose is 3.2×10¹⁵ cm^-3 and annealed at 855 ℃ for 20 min, the passivation properties of 70 nm ultra-thin poly-silicon is comparable to that of conventional 120 nm poly-silicon, and the surface doping concentration value of 5.6×10²⁰ atoms/cm³ for 70 nm ultra-thin poly-silicon is achieved, which is much higher than that of 120 nm doped poly-silicon (2.5×10²⁰ atoms/cm³). Based on the characteristic of reduced thickness and heavy doping for 70 nm ultra-thin poly-silicon, the conversion efficiency of TOPCon solar cells processed on large area (6 inch) Cz wafers significantly improves due to the low parasitic absorption and excellent filed passivation effect. The I_sc is increased by 20 mA and 0.3% improvement of FF, leading to an absolute efficiency gain of 0.13% for the champion conversion efficiency, as well as low series resistance.

Key words: TOPCon solar cell, poly-silicon, doping, ion implantation, passivation contact, parasitic absorption, photoelectric conversion efficiency

中图分类号:

TM914.4

宋志成, 杨露, 张春福, 刘大伟, 倪玉凤, 张婷, 魏凯峰. 超薄多晶硅的掺杂、钝化及光伏特性研究[J]. 人工晶体学报, 2022, 51(3): 434-440.

SONG Zhicheng, YANG Lu, ZHANG Chunfu, LIU Dawei, NI Yufeng, ZHANG Ting, WEI Kaifeng. Doping, Passivation and Photovoltaic Properties of Ultra-Thin Poly-Silicon[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2022, 51(3): 434-440.

参考文献

[1] NANDAKUMAR N, RODRIGUEZ J, KLUGE T, et al. 21.6% monoPoly^TM cells with in situ interfacial oxide and poly-Si layers deposited by inline PECVD[C]//2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC). June 10-15, 2018, Waikoloa, HI, USA. IEEE, 2018: 2048-2051.
[2] CHEN Y, CHEN D, ALTERMATT P P, et al. 25% large area industrial silicon solar cell[C].Learning From History and Future Perspective. in: 36th EUPVSEC, Marseille, France, Proc. 36th EUPVSEC, 2019.
[3] GREEN M A, KEITH E, YOSHIHIRO H, et al. Solar cell efficiency tables (version 49)[J]. Progress in Photovoltaics, 2017, 25(1): 3-13.
[4] RICHTER A, BENICK J, FELDMANN F, et al. N-type Si solar cells with passivating electron contact: identifying sources for efficiency limitations by wafer thickness and resistivity variation[J]. Solar Energy Materials and Solar Cells, 2017, 173: 96-105.
[5] HAASE F, HOLLEMANN C, SCHFER S, et al. Laser contact openings for local poly-Si-metal contacts enabling 26.1%-efficient POLO-IBC solar cells[J]. Solar Energy Materials and Solar Cells, 2018, 186: 184-193.
[6] PADHAMNATH P, WONG J, NAGARAJAN B, et al. Metal contact recombination in monoPoly^TM solar cells with screen-printed & fire-through contacts[J]. Solar Energy Materials and Solar Cells, 2019, 192: 109-116.
[7] WU Y, STODOLNY M K, GEERLIGS L J, et al. In-situ doping and local overcompensation of high performance LPCVD polysilicon passivated contacts as approach to industrial IBC cells[J]. Energy Procedia, 2016, 92: 427-433.
[8] FELDMANN F, FELLMETH T, STEINHAUSER B, et al. Large area TOPCon cells realized by a PECVD tube process[C]//36th European Photovoltaic Solar Energy Conference and Exhibition. 2019.
[9] DUTTAGUPTA S, NANDAKUMAR N, PADHAMNATH P, et al. mono Poly^TM cells: large-area crystalline silicon solar cells with fire-through screen printed contact to doped polysilicon surfaces[J]. Solar Energy Materials and Solar Cells, 2018, 187: 76-81.
[10] LIMODIO G, YANG G, GE H, et al. Front and rear contact Si solar cells combining high and low thermal budget Si passivating contacts[J]. Solar Energy Materials and Solar Cells, 2019, 194: 28-35.
[11] REITER S, KOPER N, REINEKE-KOCH R, et al. Parasitic absorption in polycrystalline Si-layers for carrier-selective front junctions[J]. Energy Procedia, 2016, 92: 199-204.
[12] DUTTAGUPTA S, NANKAKUMAR N, RODRIGUEZ J W, et al. monoPoly^TM Technology platform for enabling passivated-contacts in PERC/T production lines[C]. The SNEC Scientific Conference, 2019.
[13] NANDAKUMAR N, RODRIGUEZ J, KLUGE T, et al. Approaching 23% with large-area monoPoly cells using screen-printed and fired rear passivating contacts fabricated by inline PECVD[J]. Progress in Photovoltaics: Research and Applications, 2018: pip.3097.
[14] CHEN D M, CHEN Y F, WANG Z G, et al. 24.58% total area efficiency of screen-printed, large area industrial silicon solar cells with the tunnel oxide passivated contacts (i-TOPCon) design[J]. Solar Energy Materials and Solar Cells, 2020, 206: 110258.
[15] CHEN Y F, CHEN D M, LIU C F, et al. Mass production of industrial tunnel oxide passivated contacts (i-TOPCon) silicon solar cells with average efficiency over 23% and modules over 345 W[J]. Progress in Photovoltaics: Research and Applications, 2019, 27(10): 827-834.
[16] LING Z P, XIN Z, WANG P Q, et al. Double-sided passivated contacts for solar cell applications: an industrially viable approach toward 24% efficient large area silicon solar cells[M]//Silicon Materials: IntechOpen, 2019:.
[17] RMER U, PEIBST R, OHRDES T, et al. Recombination behavior and contact resistance of n⁺ and p⁺ poly-crystalline Si/mono-crystalline Si junctions[J]. Solar Energy Materials and Solar Cells, 2014, 131: 85-91.