Progress in screen-printed metallization of industrial solar cells with SiOx/poly-Si passivating contacts

• Published in: Solar energy materials and solar cells Vol. 218; p. 110751
• Main Authors: Padhamnath, Pradeep, Khanna, Ankit, Balaji, Nagarajan, Shanmugam, Vinodh, Nandakumar, Naomi, Wang, Deng, Sun, Qian, Huang, Ming, Huang, Shumei, Fan, Baobing, Ding, Bingbing, Aberle, Armin G., Duttagupta, Shubham
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.12.2020; Elsevier BV
• Subjects: Chemical vapor deposition; Efficiency; Electric contacts; Electrical properties; Industrial; Low pressure; Metallization; Metallizing; Optical properties; Passivated contacts; Pastes; Photovoltaic cells; Polysilicon; Recombination; Screen-printed; Solar cells; Polysilicon; Metallization; Screen-printed; Industrial; Passivated contacts
• ISSN: 0927-0248; 1879-3398
• DOI: 10.1016/j.solmat.2020.110751

Solar cells with polysilicon-based passivating and carrier selective contacts are in the nascent stages of industrialization. Advances in commercially available metallization pastes are necessary to further improve the efficiency of industrial polysilicon-based solar cells and approach the best-reported lab efficiency of such cells. In this work, we have analyzed the front and rear screen-printed metallization of large-area n-type monoPolyTM cells with rear-side low-pressure chemical vapor deposited (LPCVD) polysilicon. Metallization pastes specifically optimized for contacting poly-Si layers are used in this work. The metallization is evaluated by studying its impact on the solar cell performance and by further electrical and optical characterization. An efficiency improvement of 0.5% absolute is demonstrated due to improvements in metallization pastes with a 23% champion cell efficiency (cell area: 244.3 cm2, busbarless metallization). An analysis of the fabricated cells indicates that the efficiency is currently limited by recombination at the front surface, both at the passivated and the metallized regions. [Display omitted] •Poly-Si based passivating contacts result in lower recombination current densities, hence, higher cell voltages.•Screen-printed, fire-through metallization enabler for mass production, with minimal loss in passivation.•Improvements in metal pastes for screen-printed and fire-through metallization result in higher cell voltages.•Cell efficiencies of 23% obtained for cells with best combination of front and rear metal paste and busbar-less grid.•Higher cell efficiencies limited by the recombination from the front surface of a rear passivated contact solar cell.