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Dopant‐Free Bifacial Silicon Solar Cells
Author(s) -
Lin Wenjie,
Dréon Julie,
Zhong Sihua,
Paratte Vincent,
Antognini Luca,
Cattin Jean,
Liu Zongtao,
Liang Zongcun,
Gao Pingqi,
Shen Hui,
Ballif Christophe,
Boccard Mathieu
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.202000771
Subject(s) - dopant , materials science , optoelectronics , silicon , anti reflective coating , indium tin oxide , doping , solar cell , contact resistance , layer (electronics) , nanotechnology
Herein, challenges in the fabrication of full dopant‐free bifacial silicon solar cells are discussed and efficient devices utilizing a MoO 3 / indium tin oxide (ITO)/Ag hole‐selective contact and ZnO/LiF x /Al electron‐selective contacts with up to 79% short‐circuit current bifaciality are demonstrated. The ZnO/LiF x /Al rear electron contact features a full‐area ZnO antireflective coating and a LiF x /Al finger contact, allowing sunlight absorption from the back side, thus producing more overall power. The ZnO/LiF x /Al electron contacts with a thinner ZnO layer and a larger contact fraction display a better selectivity and a lower resistance loss. When considering rear‐side irradiance of 0.15 sun, the dopant‐free bifacial solar cell with 60 nm ZnO and 50% LiF x /Al metal contact fraction achieves a 3% estimated output power density improvement compared with its monofacial counterpart (21.0 mW cm −2 compared to 20.3 mW cm −2 ) using the full‐area back contact. Both the efficiency and bifaciality factor of this dopant‐free device are still significantly lower than those of state‐of‐the‐art devices relying on doped‐silicon‐based layers. The required improvement for this technology to become industry‐relevant is discussed.