Xu Shan, Ding Xue, Shi Huafeng, Zhang Xinhai, Sun Xiaowei, Ji Ning, Zhang Xiaoli, Zhang Zhaoyu
School of Science and Engineering and Shenzhen Key Lab of Semiconductor Lasers, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China.
School of Physics and Optoelectronic Engineering, Yangtze University, Jingzhou, Hubei 434023, China.
ACS Omega. 2021 Mar 8;6(10):7157-7164. doi: 10.1021/acsomega.1c00213. eCollection 2021 Mar 16.
One recent development to improve optoelectronic properties of perovskites is to use a larger cation for multication engineering. The chain-like ethylammonium (EA) [(CH)NH] cation is more likely to form a one-dimensional perovskite structure; however, there is no remarkable evidence in this connection. Therefore, in this work, for the first time, the EA cation as an alternative cation was introduced into FAPbBr cubic crystals to explore the stabilities and optoelectronic properties of mixed FA EAPbBr perovskites. The results indicate that replacing FA with EA is a more effective way to realize band gap tuning and morphology transformation between the cubic shape and microwires. The tuned band gap of perovskite is due to the variation of Pb-Br-Pb angles induced by the insertion of the larger EA cation. We highlight that this work provides new physical insights into the correlation between the engineering of organic cations and the formation of perovskite microwires and the tunable band gap. This observation will help us to find new ways to grow perovskite microwires and subsequently study the optoelectronic performance of low-dimensional perovskites devices.
最近为改善钙钛矿的光电性能而出现的一个进展是，在多阳离子工程中使用更大的阳离子。链状的乙铵（EA）[(CH)NH]阳离子更有可能形成一维钙钛矿结构；然而，目前尚无这方面的显著证据。因此，在本工作中，首次将EA阳离子作为替代阳离子引入FAPbBr立方晶体中，以探索混合FA EAPbBr钙钛矿的稳定性和光电性能。结果表明，用EA取代FA是实现带隙调节以及立方形状与微线之间形态转变的更有效方法。钙钛矿带隙的调节是由于插入较大的EA阳离子导致Pb-Br-Pb角度发生变化。我们强调，这项工作为有机阳离子工程与钙钛矿微线的形成以及可调带隙之间的相关性提供了新的物理见解。这一发现将有助于我们找到生长钙钛矿微线的新方法，并随后研究低维钙钛矿器件的光电性能。
