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Towards bifacial silicon heterojunction solar cells with reduced TCO use
Author(s) -
Han Can,
Santbergen Rudi,
Duffelen Max,
Procel Paul,
Zhao Yifeng,
Yang Guangtao,
Zhang Xiaodan,
Zeman Miro,
Mazzarella Luana,
Isabella Olindo
Publication year - 2022
Publication title -
progress in photovoltaics: research and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.286
H-Index - 131
eISSN - 1099-159X
pISSN - 1062-7995
DOI - 10.1002/pip.3550
Subject(s) - materials science , doping , optoelectronics , indium tin oxide , solar cell , heterojunction , transparent conducting film , contact resistance , silicon , tin oxide , nanotechnology , thin film , layer (electronics)
Abstract Reducing indium consumption, which is related to the transparent conductive oxide (TCO) use, is a key challenge for scaling up silicon heterojunction (SHJ) solar cell technology to terawatt level. In this work, we developed bifacial SHJ solar cells with reduced TCO thickness. We present three types of In 2 O 3 ‐based TCOs, tin‐, fluorine‐, and tungsten‐doped In 2 O 3 (ITO, IFO, and IWO), whose thickness has been optimally minimized. These are promising TCOs, respectively, from post‐transition metal doping, anionic doping, and transition metal doping and exhibit different opto‐electrical properties. We performed optical simulations and electrical investigations with varied TCO thicknesses. The results indicate that (i) reducing TCO thickness could yield larger current in both monofacial and bifacial SHJ devices; (ii) our IWO and IFO are favorable for n ‐contact and p ‐contact, respectively; and (iii) our ITO could serve well for both n ‐contact and p ‐contact. Interestingly, for the p ‐contact, with the ITO thickness reducing from 75 nm to 25 nm, the average contact resistivity values show a decreasing trend from 390 mΩ cm 2 to 114 mΩ cm 2 . With applying 25‐nm‐thick front IWO in n ‐contact, and 25‐nm‐thick rear ITO use in p ‐contact, we obtained front side efficiencies above 22% in bifacial SHJ solar cells. This represents a 67% TCO reduction with respect to a reference bifacial solar cell with 75‐nm‐thick TCO on both sides.