EU PVSEC Programme Online
EU PVSEC 2020, 7 - 11 September 2020
Presentation: 2BO.4.2 Design and Optimization of Positive-Charge Carrier Collectors Based on nc-SiOx:H for High-Efficiency Silicon Heterojunction Solar Cells
Type: Oral
Date: Tuesday, 8th September 2020
15:15 - 16:45
Author(s): Y. Zhao, P.A. Procel Moya, L. Mazzarella, C. Han, G. Yang, A.W. Weeber, M. Zeman, O. Isabella
Presenter / Speaker: Y. Zhao, Delft University of Technology, Delft, Netherlands
Event: Conference Conference
Session: 2BO.4 Si-Alloy Based Functional Layers and TCOs
Type(s) of Access:  Conference Registration
Topic: 2. 3 Low Temperature Route for Si Cells
Summary / Abstract: P-contacts with low activation energy (Ea) and wide bandgap (Eg) are critical for achieving effective positive-charge collection in silicon heterojunction (SHJ) solar cells. In this work, we firstly investigate and optimize PECVD p-type hydrogenated nanocrystalline silicon oxide, (p)nc-SiOx:H, and then combine it with (p)nc-Si:H as p-contact stack in front/back-contacted (FBC) SHJ solar cells. We optimize interface treatments to accelerate the nucleation of thin nanocrystalline film to obtain a lower Ea within a limited thickness. At cell level, we observe higher FF when using (p)nc-SiOx:H with an increased difference between the optical bandgap (E04) and Ea, which enhances the c-Si band bending. Further thickness optimizations of p-contact are conducted based on observed thickness-dependent Ea of the p-contact. With the guidance of electrical simulation studies [1], we obtain front and rear junction cells with FF above 80% and independently certified efficiency of 22.47%.