Excellent surface passivation of p-type TOPCon enabled by ozone-gas oxidation with a single-sided saturation current density of ～ 4.5 fA/cm2

作者：Lin, Na; Yang, Zhenhai; Du, Haojiang; Ding, Zetao; Liu, Zunke; Xing, Haiyang; Xiao, Mingjing; Ou, Yali; Liu, Wei; Liao, Mingdun; Yan, Baojie; Huang, Shihua^*; Zeng, Yuheng^*; Ye, Jichun^*

来源：Solar Energy, 2023, 259: 348-355.

DOI：10.1016/j.solener.2023.05.028

• Ozone gas(O-3) oxidation
• p-Type TOPCon
• Boron-doped polysilicon
• Passivation quality
• PECVD

High-quality p-type tunnel oxide passivated contact (p-type TOPCon) is a feasible technical solution to further improve the efficiency of TOPCon silicon solar cells. Plasma-enhanced chemical vapor deposition (PECVD) technology route could deposit boron-doped amorphous silicon film in-situ and thus becomes one of the most promising industry routes to prepare the TOPCon structure. However, the passivation quality of p-type TOPCon by PECVD is not satisfactory till now. In this work, we develop the high-performance p-type TOPCon technology by integrating the ozone-gas oxidation to prepare the ultra-thin SiOx film, which shows excellent passivation and contact properties. The experimental results suggest that the double-sided p-type TOPCon passivated samples with p-type Si substrates receive a maximal implied open-circuit voltage (iV(oc)) of similar to 734 mV together with a minimum single-sided saturation current density (J(0,s)) of similar to 4.5 fA/cm(2). Correspondingly, the contact resistivity is less than 5 m Omega center dot cm(2), yielding a high selectivity S-10 of 15.6, which is one of the best values for p-type TOPCon technology. As a result, the precursor cell manifests an excellent iV(oc) of 717 mV, and the p-type silicon solar cell with rear-sided p-type TOPCon passivating contact receives a high efficiency of 22.23%. Generally, this work provides a promising technology for preparing the high-quality p-type TOPCon passivating contact for industrial application.

• 单位
  浙江师范大学; 中国科学院宁波材料技术与工程研究所