Hydrogen Sulfide Passivation for p-Type Passivated Emitter and Rear Contact Solar Cells
Date
2023-12-11
Journal Title
Journal ISSN
Volume Title
Publisher
IEEE Journal of Photovoltaics
Abstract
This work reports on the application of sulfur (S)-passivation to passivated emitter and rear contact (PERC) solar cells. The emitter surface was passivated by hydrogen sulfide (H 2 S) gas phase reaction and capped by a hydrogenated amorphous silicon nitride (a-SiN x :H) layer. The sulfur passivation on a symmetrically n + diffused emitter is shown to lead to an emitter saturation current density (J 0n+ ) of 30 fA/cm 2 at R sheet,n+ ≈ 100 Ω/sq. The application of S-passivation to the emitter surface in the PERC cell structure, with the rear surface passivated by an aluminum oxide (Al 2 O 3 )/a-SiN x :H stack, showed a promising implied open-circuit voltage (iV OC ) of 686 mV before metallization. This iV OC was higher than that for the a-SiN x :H or SiO 2 /a-SiN x :H passivated emitter surfaces (675 and 674 mV, respectively) on PERC cells processed in the same run. However, a significant drop in cell V OC is observed for the S-passivated PERC cell after the completion of device fabrication with laser patterning, screen-printed metal contact deposition, and firing. Nonetheless, an efficiency of ∼20% and a V OC of ∼650 mV was achieved with an emitter surface passivated by sulfur. We identified that the 760 °C contact firing process degrades the S-passivation quality. The surface morphology was studied, and a detailed surface analysis was performed to study the causes of the S-passivated surface degradation.
Description
This article was originally published in IEEE Journal of Photovoltaics. The version of record is available at: https://doi.org/10.1109/JPHOTOV.2023.3338095. © 2023 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. This article will be embargoed until 12/11/2025.
Keywords
Hydrogen sulfide (H $_2$ S) reaction passivation, N $_{+}$ diffused emitter, p-PERC cell, screen printed metal contact firing, X-ray photoelectron spectroscopy (XPS)
Citation
T. K. Mouri et al., "Hydrogen Sulfide Passivation for p-Type Passivated Emitter and Rear Contact Solar Cells," in IEEE Journal of Photovoltaics, vol. 14, no. 2, pp. 211-218, March 2024, doi: 10.1109/JPHOTOV.2023.3338095