CO 2 Plasma Treatment To Prepare the Rear Emitter with a Boron-Doped Hydrogenated Amorphous/Nanocrystalline Silicon Stack for a High-Efficiency Silicon Heterojunction Solar Cell

作者：Lilan Wen, Lei Zhao, Guanghong Wang, Xiaojie Jia, Xiaohua Xu, Xiaotong Li, Shiyu Qu, Xianyang Zhang, Yuhua Zuo, Xin Ke, Xinyi Zhang, Zhigang Mei, Jihong Xiao, Su Zhou, Wenjing Wang · 发表于：ACS Applied Materials & Interfaces · 年份：2025 · DOI：10.1021/acsami.4c22110 · 被引用次数：8 · 研究领域：Silicon and Solar Cell Technologies、Thin-Film Transistor Technologies、Photovoltaic System Optimization Techniques

A rear emitter with a p-type boron-doped hydrogenated amorphous silicon/nanocrystalline silicon [a-Si:H(p)/nc-Si:H(p)] stack was prepared for the silicon heterojunction (SHJ) solar cell to improve its short-circuit current density ( J SC ). CO 2 plasma treatment (CO 2 PT) was applied to a-Si:H(p) to facilitate the crystallization of the subsequently deposited nc-Si:H(p). To evaluate the effect of the CO 2 PT, two different nc-Si:H(p) layers with low and high crystallinity (χ C ) were investigated. For the emitter with low crystallinity (χ C = 21%), the solar cell efficiency could boost from 23.6 to 25.0% with a 10 s short-time CO 2 PT primarily due to the significant increase in fill factor (FF) and J SC . χ C of the emitter increased to 41%. For the emitter with high crystallinity (χ C = 60%), the solar cell efficiency increased from 25.1 to 25.2% with a 7 s short-time CO 2 PT. χ C of the emitter increased to 70%. The corresponding improvement mechanisms were analyzed by combining high-resolution transmission electron microscopy (HRTEM) and external quantum efficiency (EQE) measurements. It is considered that an appropriate short-time CO 2 PT to a-Si:H(p) can make the subsequent nc-Si:H(p) more transparent and conductive by facilitating its crystallization without deteriorating the underneath passivation layer. Thus, the solar cell efficiency can be improved, especially with the enhanced FF and J SC . As a demonstration, the SHJ solar cell with the CO 2 PT-treated a-Si:H(p)/...