Constructing efficient mixed-ion perovskite solar cells based on TiO2 nanorod array

Longkai Yang; Xin Wang; Xianmin Mai; Tan Wang; Chao Wang; Xin Li; Vignesh Murugadoss; Qian Shao; Subramania Angaiah; Zhanhu Guo

doi:10.1016/j.jcis.2018.09.045

Constructing efficient mixed-ion perovskite solar cells based on TiO₂ nanorod array

J Colloid Interface Sci. 2019 Jan 15:534:459-468. doi: 10.1016/j.jcis.2018.09.045. Epub 2018 Sep 14.

Authors

Longkai Yang¹, Xin Wang¹, Xianmin Mai², Tan Wang³, Chao Wang⁴, Xin Li⁵, Vignesh Murugadoss⁶, Qian Shao⁷, Subramania Angaiah⁸, Zhanhu Guo⁹

Affiliations

¹ Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen 361005, China.
² School of Urban Planning and Architecture, Southwest Minzu University, Chengdu 610041, China. Electronic address: maixianmin@foxmail.com.
³ College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
⁴ Integrated Composites Laboratory (ICL), Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, United States; College of Materials Science and Engineering, North University of China, Taiyuan 030051, China.
⁵ Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen 361005, China. Electronic address: lixin01@xmu.edu.cn.
⁶ Integrated Composites Laboratory (ICL), Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, United States; Electrochemical Energy Research Lab, Centre for Nanoscience and Technology, Pondicherry University, Puducherry 605 014, India.
⁷ College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao 266590, China.
⁸ Electrochemical Energy Research Lab, Centre for Nanoscience and Technology, Pondicherry University, Puducherry 605 014, India. Electronic address: a.subramania@gmail.com.
⁹ Integrated Composites Laboratory (ICL), Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, United States. Electronic address: zguo10@utk.edu.

PMID: 30248615
DOI: 10.1016/j.jcis.2018.09.045

Abstract

Oriented TiO₂ nanorod array (TiO₂ NA) is very attractive in the fields of halide perovskite solar cells (PSCs) due to its fewer grain boundaries and high crystallinity for effective charge collection. The optimization of TiO₂ nanostructures has been proved to be an effective approach for efficient PSCs. On the other hand, tuning the crystallization of perovskite films on top of the TiO₂ NA is very important for efficient TiO₂-NA based PSCs. Herein, scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) were used to study the crystallization of different mixed-ion Cs_0.1(FA_0.83MA_0.17)_0.9Pb(I_0.83Br_0.17)₃ perovskite (in which MA = CH₃NH₃⁺, and FA = CH(NH₂)₂⁺) films, from different perovskite precursor concentrations, on the TiO₂ nanorod arrays. A mechanism was proposed to reveal the inherent connection between the precursor concentration and the crystallite growth of the perovskite film prepared with anti-solvent quenching process. Meanwhile, both faster charge separation at perovskite/TiO₂ NA interface and longer charge transport were observed on thicker perovskite film with larger grains, revealed by the time-resolved method. However, atomic force microscopy (AFM) results indicated that too thick perovskite film impaired the charge collection owing to the increased recombination. By balancing the charge collection and film thickness, highly efficient PSCs were prepared with a champion power conversion efficiency (PCE) of 19.33% with little hysteresis. The study highlights a great potential of incorporating oriented one-dimensional electron extraction materials in high-performance PSCs and other applications.

Keywords: Mixed-ion; Nanorod array; Perovskite solar cell; TiO(2).