Highly efficient deep-blue emitting CsPbBr3 nanoplatelets synthesized via surface ligand-mediated strategy

Xue Zhang; Yanyu Cui; Siyuan Ye; Zhuohan Lin; Yan Li

doi:10.1016/j.jcis.2024.03.202

Highly efficient deep-blue emitting CsPbBr₃ nanoplatelets synthesized via surface ligand-mediated strategy

J Colloid Interface Sci. 2024 Mar 30:668:68-76. doi: 10.1016/j.jcis.2024.03.202. Online ahead of print.

Authors

Xue Zhang¹, Yanyu Cui¹, Siyuan Ye¹, Zhuohan Lin¹, Yan Li²

Affiliations

¹ Key Laboratory for Advanced Materials, Shanghai Key Laboratory of Functional Materials Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China.
² Key Laboratory for Advanced Materials, Shanghai Key Laboratory of Functional Materials Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China. Electronic address: yli@ecust.edu.cn.

PMID: 38669997
DOI: 10.1016/j.jcis.2024.03.202

Abstract

Two-dimensional (2D) CsPbBr₃ nanoplatelets (NPLs) have attracted great attention as one of promising semiconductor nanomaterials due to their large exciton binding energy and narrow emission spectra. However, the labile ionic and weakly bound surfaces of deep-blue emitting CsPbBr₃ NPLs with wide bandgap result in their colloidal instability, thus degrading their optical properties. It is challenging to obtain deep-blue emitting CsPbBr₃ NPLs with excellent optical properties. In this study, high-quality blue-emitting CsPbBr₃ NPLs with tunable thickness were prepared adopting the DBSA-mediated confinement effect based on the hot-injection method. Thanks to the coordination interaction of - SO₃^- of DBSA ligand and the Pb²⁺ on the surface of the CsPbBr₃ NPLs, as well as the effective passivation of Br vacancy defects on the surface of NPLs by OAm-Br, the obtained pure-blue CsPbBr₃ NPLs and deep-blue CsPbBr₃ NPLs show high photoluminescence quantum yield (PLQY) of 92 % and 81.2 %, respectively. To the best of our knowledge, this is the highest PLQY recorded for deep-blue emitting CsPbBr₃ NPLs with two monolayers [PbBr₆]^4- octahedra. Furthermore, the agglomeration of CsPbBr₃ NPLs due to ligand loss induced by moisture, oxygen, and irradiation was also suppressed by the dual passivation effect of DBSA and OAm-Br. Our work provided a new approach to developing high-performance and stable deep-blue emitting CsPbBr₃ perovskite nanoplatelets.

Keywords: Confinement effect; CsPbBr(3) perovskite; Deep-blue emitting; Nanoplatelets.