Lee Jin-Wook, Tan Shaun, Han Tae-Hee, Wang Rui, Zhang Lizhi, Park Changwon, Yoon Mina, Choi Chungseok, Xu Mingjie, Liao Michael E, Lee Sung-Joon, Nuryyeva Selbi, Zhu Chenhui, Huynh Kenny, Goorsky Mark S, Huang Yu, Pan Xiaoqing, Yang Yang
Department of Materials Science and Engineering, California NanoSystems Institute, University of California, Los Angeles, CA, 90095, USA.
Department of Nanoengineering, SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, 16419, Republic of Korea.
Nat Commun. 2020 Nov 2;11(1):5514. doi: 10.1038/s41467-020-19237-3.
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 (FAPbI) perovskite films. The layered perovskite templates the solid-state phase conversion of FAPbI 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-FAPbI showed efficiencies and stabilities superior to those of devices fabricated without NHE.
半导体薄膜的传统外延生长需要兼容的单晶衬底和精确控制的生长条件，这限制了该工艺的价格竞争力和通用性。我们展示了高质量甲脒铅三碘化物（FAPbI）钙钛矿薄膜的衬底容忍纳米异质外延（NHE）。层状钙钛矿引导FAPbI从其六方非钙钛矿相到立方钙钛矿多晶型物的固态相转变，其中生长动力学由应变和熵之间的协同效应控制。缓慢的异质外延晶体生长使钙钛矿晶体增大了10倍，同时缺陷密度降低且择优取向强烈。这种NHE很容易应用于用于器件的各种衬底。基于NHE-FAPbI的概念验证太阳能电池和发光二极管器件表现出优于未采用NHE制造的器件的效率和稳定性。
