title: Quantitative analysis of the size effect of room temperature nanoimprinted P3HT nanopillar arrays on the photovoltaic performance.
abstract: We develop a solvent-assisted room temperature nanoimprint lithography (SART-NIL) technique to fabricate an ideal active layer consisting of poly(3-hexylthiophene) nanopillar arrays surrounded by [6,6]-phenyl-C61-butyric acid methyl ester. Characterization by scanning electron microscopy, two-dimensional grazing incidence wide angle X-rays diffraction, and conducting atomic force microscopy reveals that the SART-NIL technique can precisely control the size of P3HT nanopillar arrays. With the decrease in diameters of P3HT nanopillar arrays, the P3HT nanopillar arrays exhibit a more preferable face-on molecular orientation, enhanced UV-vis absorption and higher conducting ability along the direction perpendicular to the substrate. The ordered bulk heterojunction film consisting of P3HT nanopillar arrays with a diameter of ∼45 nm (OBHJ-45) gives face-on orientation, a high interfacial area of 2.87, a high conducting ability of ∼130 pA and efficient exciton diffusion and dissociation. The polymer solar cell (PSC) based on an OBHJ-45 film exhibits a significantly improved device performance compared with those of PSCs based on the P3HT nanoapillar arrays with diameters ∼100 nm and ∼60 nm. We believe that the SART-NIL technique is a powerful tool for fabricating an ideal active layer for high performance PSCs.
authors.affiliation: Center for Soft Condensed Matter Physics and Interdisciplinary Research & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123, China. zhijun.hu@suda.edu.cn.
authors.forename: Guangzhu
authors.initials: G
authors.lastname: Ding
authors.forename: Chao
authors.initials: C
authors.lastname: Li
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Li
authors.forename: Yangjiang
authors.initials: Y
authors.lastname: Wu
authors.forename: Jieping
authors.initials: J
authors.lastname: Liu
authors.forename: Yaowen
authors.initials: Y
authors.lastname: Li
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Hu
authors.forename: Yongfang
authors.initials: Y
authors.lastname: Li