Wei Yi, Jiang Xue, Lin Yiren, Yang Xichuan, Li Guohui, Liu Xuyang, Li Ping, Liu Aimin
School of Physics and Optoelectronic Engineering, Dalian University of Technology Dalian 116024 China
State Key Laboratory of Fine Chemicals, Institute of Artificial Photosynthesis, DUT-KTH Joint Education and Research Centre on Molecular Devices, Dalian University of Technology Dalian 116024 Liaoning China.
RSC Adv. 2019 Feb 26;9(12):6681-6688. doi: 10.1039/c8ra09433k. eCollection 2019 Feb 22.
This paper aims to develop high quality screen-printed Al emitters and improve the interface condition of rear contacts in industrial silicon solar cells. We propose to introduce an ultra-thin SiO buffer layer between the silicon bulk and metal contact during the fabrication process. A post-annealing strategy is adapted to further modify the Al doping profiles. The experimental results show that the effects of this oxide layer on migrating the nonuniformity of Al-p region and decreasing the defects at the metal-silicon interface are significant. The recombination velocity of contacts, which is extracted from the measured by an analytical model, exhibits a decrease by 90.8% and the series resistance is reduced by 60.3% for the improved contacts compared to the conventional screen-printed contacts. Finally, this technique is applied to large-area (156 × 156 mm) industrial n-type silicon solar cells and leads to a 2.18% increase in average cell efficiency, including a 12.82 mV increase in open-circuit voltage and 0.99 mA cm increase in short-circuit current density compared with solar cells fabricated by a standard industrial process. A 19.16% efficient cell with a of 637.47 mV is achieved.
本文旨在开发高质量的丝网印刷铝发射极，并改善工业硅太阳能电池背面接触的界面条件。我们建议在制造过程中，在硅体和金属接触之间引入超薄的SiO缓冲层。采用后退火策略进一步调整铝掺杂分布。实验结果表明，该氧化层对迁移铝p区的不均匀性和减少金属-硅界面处的缺陷具有显著效果。通过分析模型从测量值中提取的接触复合速度，与传统丝网印刷接触相比，改进后的接触复合速度降低了90.8%，串联电阻降低了60.3%。最后，该技术应用于大面积（156×156mm）工业n型硅太阳能电池，与采用标准工业工艺制造的太阳能电池相比，平均电池效率提高了2.18%，包括开路电压增加12.82mV和短路电流密度增加0.99mA/cm²。实现了效率为19.16%、开路电压为637.47mV的电池。
