title: Designing nanobowl arrays of mesoporous TiO₂ as an alternative electron transporting layer for carbon cathode-based perovskite solar cells.
abstract: In this work, we have designed a mesoporous TiO2 nanobowl (NB) array with pore size, bowl size and film thickness being easily controllable by the sol-gel process and the polystyrene (PS) template diameter. Based on the TiO2 NB array, we fabricated carbon cathode based perovskite solar cells (C-PSCs) to investigate the impact of TiO2 NB nanostructures on the performance of the as-obtained C-PSCs devices. As expected, the TiO2 NB based devices show a higher power conversion efficiency (PCE) than that of the planar counterpart, mainly due to the enhanced light absorption arising from the NB-assisted light management, the improved pore-filling of high quality perovskite crystals and the increased interface contact for rapid electron extraction and fast charge transport. Leveraging these advantages of the novel TiO2 NB film, the 220 nm-PS templated TiO2 NB based devices performed the best on both light absorption capability and charge extraction, and achieved a PCE up to 12.02% with good stability, which is 37% higher than that of the planar counterpart. These results point to a viable and convenient route toward the fabrication of TiO2 ETL nanostructures for high performance PSCs.
authors.affiliation: Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Zheng
authors.affiliation: Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Zhanhua
authors.initials: Z
authors.lastname: Wei
authors.affiliation: Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Haining
authors.initials: H
authors.lastname: Chen
authors.affiliation: Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Qianpeng
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Hexiang
authors.initials: H
authors.lastname: He
authors.affiliation: Nano Science and Technology Program, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China. chsyang@ust.hk.
authors.forename: Shuang
authors.initials: S
authors.lastname: Xiao
authors.affiliation: Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Fan
authors.affiliation: Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Kam Sing
authors.initials: KS
authors.lastname: Wong
authors.affiliation: Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China and Nano Science and Technology Program, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China. chsyang@ust.hk.
authors.forename: Shihe
authors.initials: S
authors.lastname: Yang