title: High-Efficiency Silicon/Organic Heterojunction Solar Cells with Improved Junction Quality and Interface Passivation.
abstract: Silicon/organic heterojunction solar cells (HSCs) based on conjugated polymers, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), and n-type silicon (n-Si) have attracted wide attention due to their potential advantages of high efficiency and low cost. However, the state-of-the-art efficiencies are still far from satisfactory due to the inferior junction quality. Here, facile treatments were applied by pretreating the n-Si wafer in tetramethylammonium hydroxide (TMAH) solution and using a capping copper iodide (CuI) layer on the PEDOT:PSS layer to achieve a high-quality Schottky junction. Detailed photoelectric characteristics indicated that the surface recombination was greatly suppressed after TMAH pretreatment, which increased the thickness of the interfacial oxide layer. Furthermore, the CuI capping layer induced a strong inversion layer near the n-Si surface, resulting in an excellent field effect passivation. With the collaborative improvements in the interface chemical and electrical passivation, a competitive open-circuit voltage of 0.656 V and a high fill factor of 78.1% were achieved, leading to a stable efficiency of over 14.3% for the planar n-Si/PEDOT:PSS HSCs. Our findings suggest promising strategies to further exploit the full voltage as well as efficiency potentials for Si/organic solar cells.
authors.affiliation: Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences , Ningbo 315201, China.
authors.forename: Jian
authors.initials: J
authors.lastname: He
authors.affiliation: Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences , Ningbo 315201, China.
authors.forename: Pingqi
authors.identifier: 0000-0002-6424-4835
authors.initials: P
authors.lastname: Gao
authors.affiliation: Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences , Ningbo 315201, China.
authors.forename: Zhaoheng
authors.initials: Z
authors.lastname: Ling
authors.affiliation: Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences , Ningbo 315201, China.
authors.forename: Li
authors.initials: L
authors.lastname: Ding
authors.affiliation: Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences , Ningbo 315201, China.
authors.forename: Zhenhai
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences , Ningbo 315201, China.
authors.forename: Jichun
authors.initials: J
authors.lastname: Ye
authors.affiliation: Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States.
authors.forename: Yi
authors.initials: Y
authors.lastname: Cui
keywords: CuI; Si/PEDOT:PSS; TMAH; hybrid solar cells; inversion layer; surface passivation