title: Characteristics of a silicon nanowires/PEDOT:PSS heterojunction and its effect on the solar cell performance.
abstract: The interfacial energy-level alignment of a silicon nanowires (SiNWs)/PEDOT:PSS heterojunction is investigated using Kelvin probe force microscopy. The potential difference and electrical distribution in the junction are systematically revealed. When the PEDOT:PSS layer is covered at the bottom of the SiNW array, an abrupt junction is formed at the interface whose characteristics are mainly determined by the uniformly doped Si bulk. When the PEDOT:PSS layer is covered on the top, a hyperabrupt junction localized at the top of the SiNWs forms, and this characteristic depends on the surface properties of the SiNWs. Because the calculation shows that the absorption of light from the SiNWs and the Si bulk are equally important, the bottom-coverage structure leads to better position matching between the depletion and absorption area and therefore shows better photovoltaic performance. The dependence of JSC and VOC on the junction characteristic is discussed.
authors.affiliation: †Siyuan Laboratory, Department of Physics, Jinan University, Guangzhou, Guangdong 510632, P. R. China.
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Liang
authors.affiliation: †Siyuan Laboratory, Department of Physics, Jinan University, Guangzhou, Guangdong 510632, P. R. China.
authors.forename: Mingze
authors.initials: M
authors.lastname: Su
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.forename: Yuting
authors.initials: Y
authors.lastname: Gong
authors.forename: Fangyan
authors.initials: F
authors.lastname: Xie
authors.forename: Li
authors.initials: L
authors.lastname: Gong
authors.affiliation: †Siyuan Laboratory, Department of Physics, Jinan University, Guangzhou, Guangdong 510632, P. R. China.
authors.forename: Hui
authors.initials: H
authors.lastname: Meng
authors.affiliation: †Siyuan Laboratory, Department of Physics, Jinan University, Guangzhou, Guangdong 510632, P. R. China.
authors.forename: Pengyi
authors.initials: P
authors.lastname: Liu
authors.forename: Huanjun
authors.initials: H
authors.lastname: Chen
authors.affiliation: †Siyuan Laboratory, Department of Physics, Jinan University, Guangzhou, Guangdong 510632, P. R. China.
authors.forename: Weiguang
authors.initials: W
authors.lastname: Xie
authors.forename: Jian
authors.initials: J
authors.lastname: Chen
keywords: built-in potential; coverage effect; cross-sectional imaging; heterojunction; silicon nanowires; solar cell