Effects of (i)a-Si

H deposition temperature on high-efficiency silicon heterojunction solar cells

Journal article (2022)

Authors

Y. Zhao Photovoltaic Materials and Devices - EEMCS
P.A. Procel Moya Photovoltaic Materials and Devices - EEMCS , University San Francisco de Quito
O. Isabella Photovoltaic Materials and Devices - EEMCS
Arno H.M. Smets Photovoltaic Materials and Devices - EEMCS
A.H.M. Smets Photovoltaic Materials and Devices - EEMCS
L. Mazzarella Photovoltaic Materials and Devices - EEMCS
C. Han Photovoltaic Materials and Devices - EEMCS
G. Yang Photovoltaic Materials and Devices - EEMCS
L. Cao Photovoltaic Materials and Devices - EEMCS
Z. Yao Photovoltaic Materials and Devices - EEMCS
A.W. Weeber Photovoltaic Materials and Devices - EEMCS , TNO
M. Zeman Electrical Sustainable Energy
Research Group
Photovoltaic Materials and Devices (EEMCS) (TU Delft)
Copyright: © 2022 Y. Zhao, P.A. Procel Moya, A.H.M. Smets, L. Mazzarella, C. Han, G. Yang, L. Cao, Z. Yao, A.W. Weeber, M. Zeman, O. Isabella
DOI: https://doi.org/10.1002/pip.3620
More Info
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Published Date

2022

Language

English

Faculty

Electrical Engineering, Mathematics and Computer Science

Department

Electrical Sustainable Energy

Research Group

Photovoltaic Materials and Devices

Abstract

Excellent surface passivation induced by (i)a-Si:H is critical to achieve high-efficiency silicon heterojunction (SHJ) solar cells. This is key for conventional single-junction cell applications but also for bottom cell application in tandem devices. In this study, we investigated the effects of (i)a-Si:H deposition temperature on passivation quality and SHJ solar cell performance. At the lower end of temperatures ranging from 140°C to 200°C, it was observed with Fourier-transform infrared spectroscopy (FTIR) that (i)a-Si:H films are less dense, thus hindering their surface passivation capabilities. However, with additional hydrogen plasma treatments (HPTs), those (i)a-Si:H layers deposited at lower temperatures exhibited significant improvements and better passivation qualities than their counterparts deposited at higher temperatures. On the other hand, even though we observed the highest VOCs for cells with (i)a-Si:H deposited at the lowest temperature (140°C), the related FFs are poorer as compared to their higher temperature counterparts. The optimum trade-off between VOC and FF for the SHJ cells was found with temperatures ranging from 160°C to 180°C, which delivered independently certified efficiencies of 23.71%. With a further improved p-layer that enables a FF of 83.3%, an efficiency of 24.18% was achieved. Thus, our study reveals two critical requirements for optimizing the (i)a-Si:H layers in high-efficiency SHJ solar cells: (i) excellent surface passivation quality to reduce losses induced by interface recombination and simultaneously (ii) less-defective (i)a-Si:H bulk to not disrupt the charge carrier collections.