Preparation Process of Emitter for p-Type TBC Cells

doi:10.16553/j.cnki.issn1000-985x.2024.0283

Abstract

Abstract: Introducing the tunneling oxide passivated contact （TOPCon） structure into the back contact solar cells structure， a tunneling oxide passivated contact back contact （TBC） solar cell was prepared， which can effectively suppress the recombination of electrons and holes， and improve the photoelectric conversion efficiency. This article focuses on the preparation process of the emitter of p-type TBC solar cells， and deeply studies the preparation process and passivation performance of n-type tunneling oxide passivation contact structures （n-TOPCon） on p-type silicon wafers. Through experiments， the influence of oxidation time on the thickness of the oxide layer during the growth process of the tunneling oxide layer was studied， and the effect of different thicknesses of tunneling oxide layers on the passivation of the emitter n-TOPCon structure was investigated. The experimental results show that at an oxidation temperature of 600 ℃ and an oxidation time of 1 200 s， the tunneling oxide layer thickness reaches 1.52 nm， and the optimal passivation performance could be obtained. At this time， the hidden implied open circuit voltage reaches 733 mV， corresponding to J₀ of 4.41 fA/cm². Afterwards， the doping distribution curve and passivation performance of n-TOPCon emitter under different phosphorus diffusion temperatures and phosphorus source flow rates were studied. When the diffusion temperature reaches 870 ℃， the implied open circuit voltage of n-TOPCon can be increased to 736 mV. As the diffusion temperature increases， the implied open circuit voltage of the emitter n-TOPCon structure begins to decrease. Finally， the relationship between the passivation performance of n-TOPCon structure and N₂-POCl₃ flow rate was studied under the same diffusion temperature. Through experiments， it is found that with the increase of diffusion N₂-POCl₃ flow rate， the passivation performance of n-TOPCon structure first improve and then decrease. According to the test results， when the N₂-POCl₃ flow rate is 3 000 sccm， the hidden open circuit voltage of n-TOPCon structure can be increased to 740 mV.

Key words: p-type TBC cell; phosphorus diffusion; LPCVD; doping; passivation performance

CLC Number:

TM914.4

SONG Zhicheng, ZHANG Bo, ZHANG Chunfu, QU Xiaoyong, NI Yufeng, GAO Jiaqing. Preparation Process of Emitter for p-Type TBC Cells[J]. Journal of Synthetic Crystals, 2025, 54(5): 857-863.

Figures/Tables 6

Fig.1 Preparation process of the sample

Fig.2 Schematic diagram of experimental sample （a） and p-type TBC cell structure （b）

Table 1 Process parameters for preparing TOPCon passivation structure films for different oxidation time

Oxidation time/s	Oxidation temperature/℃	Polysilicon deposition temperature/℃	Polysilicon thickness/nm
400	600	600	140
800	600	600	140
1 200	600	600	140
1 600	600	600	140
2 000	600	600	140

Fig.3 Thickness of tunneling oxide layer （a）， passivation effect （b）， and saturation current density （c） for different oxidation time

Fig.4 Phosphorus doping distribution curves （a） and passivation effect （b） at different diffusion temperatures

Fig.5 Phosphorus doping distribution curve （a） and passivation effect （b） with different N2-POCl3 flow rates

References 18

1	IRENA. Global energy transformation： A roadmap to 2050 （2019 edition）［DB/OL］. 2019. https://www.irena.org/publications.
2	CUEVAS A， LUQUE A， EGUREN J， et al. High efficiency bifacial back surface field solar cells［J］. Solar Cells， 1981， 3（4）： 337-340.
3	ZHANG T J， QU X Y， GUO Y G， et al. The passivation characteristics of poly-Si/SiOx stack for high-efficiency silicon solar cells［J］. Silicon， 2023， 15（4）： 1659-1668.
4	王文静，李海玲，周春兰，等. 晶体硅太阳电池制造技术［M］. 北京：机械工业出版社， 2014： 325.
	WANG W J， LI H L， ZHOU C L， et al. Manufacturing technology of crystalline silicon solar cells［M］. Beijing： Machinery Industry Press， 2014： 325 （in Chinese）.
5	SCHWARTZ R J， LAMMERT M D. Silicon solar cells for high concentration applications［C］// 1975 International Electron Devices Meeting. December 1-3， 1975， Washington， DC， USA. IEEE， 2005： 350-352.
6	ROSE D， RIM S. Development and production of high performance silicon cells for PV panels and LCPV systems［C］// Proceedings of the IEEE PVSC. Denver， USA， 2014： 491-494.
7	REICHEL C， MÜLLER R， FELDMANN F， et al. Influence of the transition region between p- and n-type polycrystalline silicon passivating contacts on the performance of interdigitated back contact silicon solar cells［J］. Journal of Applied Physics， 2017， 122（18）： 184502.
8	任程超，周佳凯，张博宇，等. 基于隧穿氧化物钝化接触的高效晶体硅太阳电池的研究现状与展望［J］. 物理学报， 2021， 70（17）： 294-304.
	REN C C， ZHOU J K， ZHANG B Y， et al. Status and prospective of high-efficiency c-Si solar cells based on tunneling oxide passivation contacts［J］. Acta Physica Sinica， 2021， 70（17）： 294-304 （in Chinese）.
9	代同光，谭　新，宋志成，等. TOPCon太阳电池单面沉积Poly-Si的工艺研究［J］. 人工晶体学报， 2024， 53（5）： 818-823.
	DAI T G， TAN X， SONG Z C， et al. Single-sided deposition of poly-Si in TOPCon solar cells［J］. Journal of Synthetic Crystals， 2024， 53（5）： 818-823 （in Chinese）.
10	HAASE F， HOLLEMANN C， SCHÄFER 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.
11	李泓霖. BC电池出圈，细分技术路线全梳理［EB/OL］. 2023. https://www.yicai.com/news/101857656.html.
	LI H L. BC battery out of cycle， detailed technical roadmap sorted out［EB/OL］. 2023. https://www.yicai.com/news/101857656.html （in Chinese）.
12	马红娜，李　锋，赵学玲，等. LPCVD制备多晶硅薄膜的性能［J］. 半导体技术， 2022， 47（8）： 630-635.
	MA H N， LI F， ZHAO X L， et al. Performances of polysilicon films prepared by LPCVD［J］. Semiconductor Technology， 2022， 47（8）： 630-635 （in Chinese）.
13	FELDMANN F， BIVOUR M， REICHEL C， et al. Tunnel oxide passivated contacts as an alternative to partial rear contacts［J］. Solar Energy Materials and Solar Cells， 2014， 131： 46-50.
14	FELDMANN F， SIMON M， BIVOUR M， et al. Efficient carrier-selective p- and n-contacts for Si solar cells［J］. Solar Energy Materials and Solar Cells， 2014， 131： 100-104.
15	TAO Y G， MADANI K， CHO E， et al. High-efficiency selective boron emitter formed by wet chemical etch-back for n-type screen-printed Si solar cells［J］. 2017， 110（2）： 021101.
16	LANCASTER K， GROßER S， FELDMANN F， et al. Study of pinhole conductivity at passivated carrier-selected contacts of silicon solar cells［J］. Energy Procedia， 2016， 92： 116-121.
17	PEIBST R， RÖMER U， LARIONOVA Y， et al. Working principle of carrier selective poly-Si/c-Si junctions： is tunnelling the whole story？［J］. Solar Energy Materials and Solar Cells， 2016， 158： 60-67.
18	马典. 高质量p型隧穿氧化钝化接触及其在高效晶硅太阳能电池的应用［D］. 昆明：云南大学， 2022.
	MA D. High-quality p-type tunneling oxide passivation contacts （p-TOPCon） and its application in TOPCon solar cells［D］. Kunming： Yunnan University， 2022 （in Chinese）.

[1]	XU Huakai, LAI Guoxia, SU Kunren, XU Xiangfu, CHE Youda, HE Yan, CHEN Xingyuan. First-Principles Study of Multiferroic Properties of V and Cr Doped TiOCl₂ Monolayer [J]. Journal of Synthetic Crystals, 2025, 54(4): 629-635.
[2]	MIN Yueqi, XIE Wenqin, XIE Liang, AN Kang. Optoelectronic Properties of CsPbX₃ (X=Cl, Br, I) Regulated by Pd Doping [J]. Journal of Synthetic Crystals, 2025, 54(4): 605-616.
[3]	MENG Xiaoyan, GAN Xin, WANG Chunyang, ZHU Yaoxian, YANG Liusai, WU Lidan, DONG Hongxia. Design, Synthesis and Luminescent Properties of CaMoO₄：Dy³⁺/Sm³⁺ White Phosphors [J]. Journal of Synthetic Crystals, 2025, 54(4): 663-673.
[4]	SHAO Meifang, FENG Jinyang, HOU Tianjiang, MA Xiao. Properties of Gadolinium Gallium Garnet Substituded with Different Stoichiometric Ratios of Ca²⁺/Mg²⁺/Zr⁴⁺ [J]. Journal of Synthetic Crystals, 2025, 54(4): 543-552.
[5]	ZHANG Jiaqi, LIN Xueling, TIAN Wenhu, MA Wenjie, ZHANG Xiu, MA Xiaowei, ZHU Qiaoping, HAO Rui, PAN Fengchun. Effect of Strain on Optical Properties of Si Doped A-TiO₂ Studied by the First-Principles [J]. Journal of Synthetic Crystals, 2025, 54(4): 617-628.
[6]	SHU Jian, LI Shengnan, JIANG Yi, JIA Zhenguo. Afterglow Performance Optimization of Dy³⁺ Doped SrAl₂O₄：Tb³⁺ Afterglow Luminescent Phosphors [J]. Journal of Synthetic Crystals, 2025, 54(4): 652-662.
[7]	LI Qi, FU Bo, YU Bowen, ZHAO Hao, LIN Na, JIA Zhitai, ZHAO Xian, TAO Xutang. First-Principle Study on the Interaction Between Al/In Doping and (100) Twins in β-Ga₂O₃ [J]. Journal of Synthetic Crystals, 2025, 54(3): 371-377.
[8]	HAN Yu, JIAO Teng, YU Han, SAI Qinglin, CHEN Duanyang, LI Zhen, LI Yihan, ZHANG Zhao, DONG Xin. Effect of Substrate Crystal Planes on the Properties of Homoepitaxial n-Ga₂O₃ Thin Films Grown by MOCVD [J]. Journal of Synthetic Crystals, 2025, 54(3): 438-444.
[9]	SUN Rujun, ZHANG Jinghui, LI Yifan, HAO Yue, ZHANG Jincheng. Review on Mg Doping of Ga₂O₃ [J]. Journal of Synthetic Crystals, 2025, 54(3): 361-370.
[10]	YAN Yuchao, WANG Cheng, LU Changcheng, LIU Yingying, XIA Ning, JIN Zhu, ZHANG Hui, YANG Deren. Growth of 2-Inch Fe-Doped β-Ga₂O₃ Single Crystal with High Resistance and Properties of (010) Substrates [J]. Journal of Synthetic Crystals, 2025, 54(2): 197-201.
[11]	YAO Suhao, ZHANG Maolin, JI Xueqiang, YANG Lili, LI Shan, GUO Yufeng, TANG Weihua. Mist CVD Grown High-Phase-Purity α-Ga₂O₃ and Its Photoresponse Performance [J]. Journal of Synthetic Crystals, 2025, 54(2): 233-243.
[12]	ZHANG Ziqi, YANG Zhenni, KUANG Siliang, WEI Shenglong, XU Wenjing, CHEN Duanyang, QI Hongji, ZHANG Hongliang. Electronic Transport Properties of Sn-Doped β-Ga₂O₃ (010) Thin Films Grown by MBE Homoepitaxial Growth [J]. Journal of Synthetic Crystals, 2025, 54(2): 244-254.
[13]	YU Xinxin, SHEN Rui, YU Han, ZHANG Zhao, SAI Qinglin, CHEN Duanyang, YANG Zhenni, QIAO Bing, ZHOU Likun, LI Zhonghui, DONG Xin, ZHANG Hongliang, QI Hongji, CHEN Tangsheng. β-Ga₂O₃ Field-Effect Transistors with Doped Epitaxial Layer Grown by MOCVD [J]. Journal of Synthetic Crystals, 2025, 54(2): 312-318.
[14]	ZHOU Lina, LIU Jianqiang, NIU Xiaowei. Growth of ø210 mm Large-Size Eu³⁺∶CaF₂ Laser Crystal [J]. Journal of Synthetic Crystals, 2025, 54(2): 358-359.
[15]	CHEN Hongming, FAN Shengqi, SONG Qi, JIANG Ling, CHEN Yongjun, LI Jianbao, ZHANG Xueyan. Preparation of Ni-Doped Mo₂C/C Bifunctional Catalysts and Their Performance in Electrolytic Water Splitting [J]. JOURNAL OF SYNTHETIC CRYSTALS, 2025, 54(1): 158-164.