title: Nonuniform Effect of Carrier Separation Efficiency and Light Absorption in Type-II Perovskite Nanowire Solar Cells.
abstract: Coaxial structures exhibit great potential for the application of high-efficiency solar cells due to the novel mechanism of radial charge separation. Here, we intensively investigate the nonuniform effect of carrier separation efficiency (CSE) and light absorption in perovskite-based type-II coaxial nanowire solar cells (ZnO/CH3NH3PbI3). Results show that the CSE rapidly decreases along the radial direction in the shell, and the value at the outer side becomes extremely low for the thick shell. Besides, the position of the main light absorption gradually moves to the outer side with the increase of the shell thickness. As a result, the external quantum efficiency shows a positional dependence with a maximal value close to the border of the nanowire. Eventually, in our case, it is found that the maximal power conversion efficiency of the solar cells reduces from 19.5 to 17.9% under the effect of the nonuniformity of CSE and light absorption. This work provides a basis for the design of high-efficiency solar cells, especially type-II nanowire solar cells.
authors.affiliation: Department of Physics, Fujian Key Laboratory of Semiconductor Materials and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Xiamen University, Xiamen, 361005, People's Republic of China.
authors.forename: Weiping
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Physics, Fujian Key Laboratory of Semiconductor Materials and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Xiamen University, Xiamen, 361005, People's Republic of China.
authors.forename: Jialun
authors.initials: J
authors.lastname: He
authors.affiliation: Department of Physics, Fujian Key Laboratory of Semiconductor Materials and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Xiamen University, Xiamen, 361005, People's Republic of China.
authors.forename: Yiyan
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Department of Physics, Fujian Key Laboratory of Semiconductor Materials and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Xiamen University, Xiamen, 361005, People's Republic of China.
authors.forename: Lijing
authors.initials: L
authors.lastname: Kong
authors.affiliation: Department of Physics, Fujian Key Laboratory of Semiconductor Materials and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Xiamen University, Xiamen, 361005, People's Republic of China. xlzheng1130@xmu.edu.cn.
authors.forename: Xuanli
authors.initials: X
authors.lastname: Zheng
authors.affiliation: Department of Physics, Fujian Key Laboratory of Semiconductor Materials and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Xiamen University, Xiamen, 361005, People's Republic of China.
authors.forename: Yaping
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Physics, Fujian Key Laboratory of Semiconductor Materials and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Xiamen University, Xiamen, 361005, People's Republic of China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Physics, Fujian Key Laboratory of Semiconductor Materials and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Xiamen University, Xiamen, 361005, People's Republic of China.
authors.forename: Shuping
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Physics, Fujian Key Laboratory of Semiconductor Materials and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Xiamen University, Xiamen, 361005, People's Republic of China. zmwu@xmu.edu.cn.
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Department of Physics, Fujian Key Laboratory of Semiconductor Materials and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Xiamen University, Xiamen, 361005, People's Republic of China. jykang@xmu.edu.cn.
authors.forename: Junyong
authors.initials: J
authors.lastname: Kang
keywords: Carrier separation efficiency; Nonuniform effect; Solar cell; ZnO/CH3NH3PbI3 coaxial nanowires