Premium
High‐Performance Europium Fluoride Electron‐Selective Contacts for Efficient Crystalline Silicon Solar Cells
Author(s) -
Zhang Linkun,
Meng Lanxiang,
Cai Lun,
Chen Zhiming,
Lin Wenjie,
Chen Nuo,
Wang Wenxian,
Shen Hui,
Liang Zongcun
Publication year - 2021
Publication title -
solar rrl
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.544
H-Index - 37
ISSN - 2367-198X
DOI - 10.1002/solr.202100057
Subject(s) - materials science , dopant , work function , crystalline silicon , doping , silicon , ohmic contact , nanotechnology , optoelectronics , solar cell , chemical engineering , analytical chemistry (journal) , layer (electronics) , chemistry , engineering , chromatography
Dopant‐free carrier‐selective contacts have attracted considerable research interests, extensively due to the avoidance of high‐temperature doping and their simple, environmental‐friendly fabrication processes for crystalline silicon (c‐Si) solar cells. Herein, a novel dopant‐free electron‐selective material, europium fluoride (EuF x ) is developed. A desired Ohmic contact can be formed between lightly doped n‐type c‐Si and aluminum (Al) by inserting nanoscale EuF x films (2–4 nm) through thermal evaporation so as to avoid the high‐temperature phosphorus diffusion and offer a simple, robust process. The contact resistivity is lower than 20 mΩ cm 2 . EuF x film can effectively select electrons and block holes at the contact interface, which is attributed to its low work function and a large valence band offset with respect to n‐type c‐Si. Combined with an ultrathin silicon oxide (SiO 2 ) as a passivation layer, a champion power conversion efficiency 21.6% of n‐type c‐Si solar cells with full‐area SiO 2 /EuF x is achieved. An average of absolute efficiency is increased by 12% compared with the reference. The results show that EuF x has particularly excellent electron‐selective transport performance. The new possibility of using lanthanide salts as electron‐selective contacts for photovoltaic (PV) devices is set up.