Enhanced passivation and stability of negative charge injected SiN_x with higher nitrogen content on the boron diffused surface of n-type Si solar cells

Journal Article · 19 May 2024 · Solar Energy Materials and Solar Cells

DOI: https://doi.org/10.1016/j.solmat.2024.112922 · OSTI ID:2352120

Min, Kwan Hong ^[1]; Hwang, Jeong-Mo  ^[2]; Chen, Christopher  ^[2]; Choi, Wook-Jin  ^[3]; Upadhyaya, Vijaykumar D. ^[3]; Bounsaville, Brian ^[3]; Rohatgi, Ajeet ^[3]; Ok, Young-Woo  ^[3]

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1. Georgia Institute of Technology, Atlanta, GA (United States); Inert Plasma Charging LLC
2. Inert Plasma Charging LLC, Chandler, AZ (United States)
3. Georgia Institute of Technology, Atlanta, GA (United States)

This paper explores the potential of the negatively charged SiN_x using plasma charge injection technology to passivate the front textured boron-diffused emitter of n-type Si solar cells. The high-x value single SiN_x layer with x ≥ 1.30 (x = N/Si) previously developed for the planarized rear-side passivation of p-type silicon solar cells, with an excellent passivation and charge stability, was found to be unacceptable for the passivation on the front textured boron emitter of n-type cells due to a severe bulk lifetime degradation issue. Therefore, in this study, we investigated a new concept of depositing a dual-x SiN_x with a low-x SiN_x layer (x~1.01) on top of a high-x SiN_x layer (x~1.30) for passivation of the front textured rough surface of boron diffused emitter in n-type cells. Here, the optimized dual-x SiN_x stack reveals the promise of charge retention for more than 25 years in field operation as well as excellent passivation of boron-doped emitter without bulk lifetime degradation. N-type cells with the optimized dual-x SiN_x after charge injection show comparable cell performance to Al₂O₃ passivated reference cells. The results of cell-level light stability tests using one-cell minimodules exhibit cell performance decay characteristics similar to the traditional Al₂O₃/SiN_x passivated reference module.

• Research Organization: Inert Plasma Charging LLC, Chandler, AZ (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office; National Science Foundation (NSF)
• Grant/Contract Number: EE0008566
• OSTI ID: 2352120
• Journal Information: Solar Energy Materials and Solar Cells, Journal Name: Solar Energy Materials and Solar Cells Vol. 273; ISSN 0927-0248
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English