Tunneling Oxidation and Passivation Process of p-Type TOPCon Structure

doi:10.16553/j.cnki.issn1000-985x.20241029.003

Abstract

Abstract: In order to further investigate the preparation process and passivation performance of p-type TOPCon structure, experimental investigations were conducted on the effects of oxygen flow rate, oxidation temperature, and oxidation time on the quality of oxide layer during the growth of tunnel oxide layer. Additionally, the passivation performance and sheet resistance of p-poly at different boron diffusion temperatures were also examined. The experimental results demonstrate that increasing the oxygen flow rate to 15 slm (standard liter per minute) leads to an average hidden open circuit voltage of 730 mV, and a dark saturation current density as low as 3.5 fA/cm² for p-poly. Furthermore, when oxidation temperature is 620 ℃ and oxidation time reaches 30 min, the imply open circuit voltage increases to 735 mV. It is observed that both increasing oxidation temperature and extending oxidation time tend to stabilize the imply open circuit voltage. Moreover, when maintaining a boron diffusion temperature at 960 ℃, a sheet resistance value of p-poly remains at 132 Ω/□ while achieving a dopant junction depth of 0.25 μm in silicon. This configuration exhibits excellent passivation performance. The determined process parameters in this study enable the preparation of p-poly structures with superior passivation performance and provide valuable data support for future industrial applications involving P-type TOPCon structures in high-efficiency crystalline silicon cells.

Key words: p-type TOPCon structure, low pressure chemical vapor deposition, passivation quality, imply open circuit voltage, dark saturation current density, solar cell

CLC Number:

TM914.4

GAO Jiaqing, QU Xiaoyong, WU Xiang, GUO Yonggang, WANG Yonggang, WANG Liang, TAN Xin, YANG Xinze. Tunneling Oxidation and Passivation Process of p-Type TOPCon Structure[J]. Journal of Synthetic Crystals, 2025, 54(1): 133-138.

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