Activating and optimizing evaporation-processed magnesium oxide passivating contact for silicon solar cells
Date
2019
Authors
Yu, Jing
Liao, Mingdun
Yan, Di
Wan, Yimao
Lin, Hao
Wang, Zilei
Gao, Pingqi
Zeng, Yuheng
Yan, Baojie
Ye, Jichun
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier BV
Abstract
Irrespective of the success on reduction of contact resistivity, lack of chemical passivation of evaporated metal oxides heavily hinders their applications as passivating contacts, such contacts can be an alternative route for high efficiency and cost effective silicon solar cells. Here, we demonstrate that electron beam evaporated magnesium oxide (MgOx) thin film can work as a promising electron-selective passivating contact for n-Si solar cells after a post-annealing treatment and an alumina-initiated atomic hydrogenation. 10 nm MgOx on n-Si provided a surface recombination velocity down to 14.9 cm/s while 1 nm MgOx showed a low contact resistivity of 14 mOcm2. Comprehensive characterizations revealed the formation of Si-O-Mg bonds and the activation of atomic hydrogens were the main reasons for such high-level passivation. A PERC-like dopant-free rear contact was formed by using the 1 nm-MgOx as electron-collector and the 10 nm-MgOx as passivating layer, the resultant solar cells achieved 27% increment in efficiency and 51 mV increase in open-circuit voltage in comparison with reference devices. The ways of improving passivation quality of MgOx and novel design of contact structure open up the possibility of using evaporation-processed metal oxides as effective and low-cost carrier-selective passivating contacts for n-Si photovoltaic devices.
Description
Keywords
Passivating contacts, Dopant-free, Carrier-selective contacts, Heterojunction silicon solar cells, Magnesium oxide (MgOx)
Citation
Collections
Source
Nano Energy
Type
Journal article
Book Title
Entity type
Access Statement
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DOI
10.1016/j.nanoen.2019.05.015
Restricted until
2099-12-31