He, JianHossain, Md. AnowerLin, HaoWang, WenjieKaruturi, Siva KrishnaHoex, BramYe, JichunGao, PingqiBullock, JamesWan, Yimao2020-03-041936-0851http://hdl.handle.net/1885/202034In order to achieve a high performance-to-cost ratio to photovoltaic devices, the development of crystalline silicon (c-Si) solar cells with thinner substrates and simpler fabrication routes is an important step. Thin-film heterojunction solar cells (HSCs) with dopant-free and carrier-selective configurations look like ideal candidates in this respect. Here, we investigated the application of n-type silicon/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) HSCs on periodic nanopyramid textured, ultrathin c-Si (∼25 μm) substrates. A fluorine-doped titanium oxide film was used as an electron-selective passivating layer showing excellent interfacial passivation (surface recombination velocity ∼10 cm/s) and contact property (contact resistivity ∼20 mΩ/cm2). A high efficiency of 15.10% was finally realized by optimizing the interfacial recombination and series resistance at both the front and rear sides, showing a promising strategy to fabricate high-performance ultrathin c-Si HSCs with a simple and low-temperature procedure.J.H. and Y.W. acknowledge the support of the Australian Renewable Energy Agency (ARENA) Research and Development Program (2017/RND007). J.Y. acknowledges the support of the National Natural Science Foundation of China (61874177). P.G. acknowledges the support of the Zhejiang Provincial Natural Science Foundation (LR19E020001) and the National Natural Science Foundation of China (61674154).7 pagesapplication/pdfen-AU© 2019 American Chemical Societyultrathin c-Si, asymmetric heterocontacts, passivating contact, titanium oxide, electron-selective contact2019-04-2410.1021/acsnano.9b017542019-11-25