Solid-phase hetero epitaxial growth of α-phase formamidinium perovskite

Jin-Wook Lee; Shaun Tan; Tae-Hee Han; Rui Wang; Lizhi Zhang; Changwon Park; Mina Yoon; Chungseok Choi; Mingjie Xu; Michael E Liao; Sung-Joon Lee; Selbi Nuryyeva; Chenhui Zhu; Kenny Huynh; Mark S Goorsky; Yu Huang; Xiaoqing Pan; Yang Yang

doi:10.1038/s41467-020-19237-3

Solid-phase hetero epitaxial growth of α-phase formamidinium perovskite

Nat Commun. 2020 Nov 2;11(1):5514. doi: 10.1038/s41467-020-19237-3.

Authors

Jin-Wook Lee^{1

2}, Shaun Tan³, Tae-Hee Han^{3

4}, Rui Wang³, Lizhi Zhang⁵, Changwon Park⁵, Mina Yoon⁶, Chungseok Choi³, Mingjie Xu⁷, Michael E Liao³, Sung-Joon Lee³, Selbi Nuryyeva³, Chenhui Zhu⁸, Kenny Huynh³, Mark S Goorsky³, Yu Huang³, Xiaoqing Pan⁷, Yang Yang⁹

Affiliations

¹ Department of Materials Science and Engineering, California NanoSystems Institute, University of California, Los Angeles, CA, 90095, USA. jw.lee@skku.edu.
² Department of Nanoengineering, SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, 16419, Republic of Korea. jw.lee@skku.edu.
³ Department of Materials Science and Engineering, California NanoSystems Institute, University of California, Los Angeles, CA, 90095, USA.
⁴ Division of Materials Science and Engineering, Hanyang University, Seoul, 04763, Republic of Korea.
⁵ Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, USA.
⁶ Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
⁷ Department of Materials Science and Engineering, Irvine Materials Research Institute, University of California, Irvine, CA, 92697, USA.
⁸ Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94704, USA.
⁹ Department of Materials Science and Engineering, California NanoSystems Institute, University of California, Los Angeles, CA, 90095, USA. yangy@ucla.edu.

Abstract

Conventional epitaxy of semiconductor films requires a compatible single crystalline substrate and precisely controlled growth conditions, which limit the price competitiveness and versatility of the process. We demonstrate substrate-tolerant nano-heteroepitaxy (NHE) of high-quality formamidinium-lead-tri-iodide (FAPbI₃) perovskite films. The layered perovskite templates the solid-state phase conversion of FAPbI₃ from its hexagonal non-perovskite phase to the cubic perovskite polymorph, where the growth kinetics are controlled by a synergistic effect between strain and entropy. The slow heteroepitaxial crystal growth enlarged the perovskite crystals by 10-fold with a reduced defect density and strong preferred orientation. This NHE is readily applicable to various substrates used for devices. The proof-of-concept solar cell and light-emitting diode devices based on the NHE-FAPbI₃ showed efficiencies and stabilities superior to those of devices fabricated without NHE.