title: High Efficiency Organic/Silicon-Nanowire Hybrid Solar Cells: Significance of Strong Inversion Layer.
abstract: Organic/silicon nanowires (SiNWs) hybrid solar cells have recently been recognized as one of potentially low-cost candidates for photovoltaic application. Here, we have controllably prepared a series of uniform silicon nanowires (SiNWs) with various diameters on silicon substrate by metal-assisted chemical etching followed by thermal oxidization, and then fabricated the organic/SiNWs hybrid solar cells with poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (
  PSS). It is found that the reflective index of SiNWs layer for sunlight depends on the filling ratio of SiNWs. Compared to the SiNWs with the lowest reflectivity (LR-SiNWs), the solar cell based on the SiNWs with low filling ratio (LF-SiNWs) has a higher open-circuit voltage and fill factor. The capacitance-voltage measurements have clarified that the built-in potential barrier at the LF-SiNWs/
  PSS interface is much larger than that at the LR-SiNWs/PEDOT one, which yields a strong inversion layer generating near the silicon surface. The formation of inversion layer can effectively suppress the carrier recombination, reducing the leakage current of solar cell, and meanwhile transfer the LF-SiNWs/
  PSS device into a p-n junction. As a result, a highest efficiency of 13.11% is achieved for the LF-SiNWs/
  PSS solar cell. These results pave a way to the fabrication of high efficiency organic/SiNWs hybrid solar cells.
authors.affiliation: State Key Laboratory of Silicon Materials and School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China.
authors.forename: Xuegong
authors.initials: X
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Silicon Materials and School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China.
authors.forename: Xinlei
authors.initials: X
authors.lastname: Shen
authors.affiliation: State Key Laboratory of Silicon Materials and School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China.
authors.forename: Xinhui
authors.initials: X
authors.lastname: Mu
authors.affiliation: Institute of Functional Nano and Soft Materials (FUNSOM) &Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Institute of Functional Nano and Soft Materials (FUNSOM) &Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123, China.
authors.forename: Baoquan
authors.initials: B
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Silicon Materials and School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China.
authors.forename: Lingsheng
authors.initials: L
authors.lastname: Zeng
authors.affiliation: State Key Laboratory of Silicon Materials and School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China.
authors.forename: Lifei
authors.initials: L
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Silicon Materials and School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China.
authors.forename: Yichao
authors.initials: Y
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Silicon Materials and School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China.
authors.forename: Hang
authors.initials: H
authors.lastname: He
authors.affiliation: State Key Laboratory of Silicon Materials and School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China.
authors.forename: Deren
authors.initials: D
authors.lastname: Yang