Fluorinated Spacers Regulate the Emission and Bandgap of Two-Dimensional Single-Layered Lead Bromide Perovskites by Hydrogen Bonding

Binbin Luo; Yan Guo; Yonghong Xiao; Xin Lian; Tongtong Tan; Dehai Liang; Xianli Li; Xiaochun Huang

doi:10.1021/acs.jpclett.9b02172

Fluorinated Spacers Regulate the Emission and Bandgap of Two-Dimensional Single-Layered Lead Bromide Perovskites by Hydrogen Bonding

J Phys Chem Lett. 2019 Sep 5;10(17):5271-5276. doi: 10.1021/acs.jpclett.9b02172. Epub 2019 Aug 27.

Authors

Binbin Luo^{1

2}, Yan Guo¹, Yonghong Xiao¹, Xin Lian¹, Tongtong Tan¹, Dehai Liang¹, Xianli Li¹, Xiaochun Huang^{1

2}

Affiliations

¹ Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province, Shantou University, Shantou, Guangdong 515063, China.
² Guangdong Provincial Laboratory of Chemistry and Fine Chemical Engineering, Shantou 515063, China.

PMID: 31438672
DOI: 10.1021/acs.jpclett.9b02172

Abstract

In this work, four kinds of two-dimensional single-layered F-substituted ethylammonium lead halide perovskites (LHPs, (F_xCH_3-xCH₂NH₃)₂PbBr₄, x = 0, 1, 2, and 3) are successfully synthesized. The introduction of terminal F atoms promotes the formation of an inter- and intramolecular hydrogen bonding network, which has a great impact on the configuration of F-substituted EA, the interlayer spacing, and distortion of inorganic layers. Among these four as-prepared samples, (FCH₂CH₂NH₃)₂PbBr₄ shows the smallest bandgap (∼2.72 eV) and best photoconductivity because of the interlayer electronic coupling. Owing to the strong coupling between excitons and lattice, intense white light emission (quantum yield: 12%) is observed for (F₂CHCH₂NH₃)₂PbBr₄. Benefiting from the hydrophobic nature of F-C bonds, (CF₃CH₂NH₃)₂PbBr₄ presents a greatly improved stability toward moisture. These findings reveal that constructing inter- and intramolecular interaction can serve as an effective approach for tuning the broadband emission and the interlayer conductivity of single-layered LHPs.