Cortecchia Daniele, Mróz Wojciech, Folpini Giulia, Borzda Tetiana, Leoncino Luca, Alvarado-Leaños Ada Lili, Speller Emily Mae, Petrozza Annamaria
Centre for Nano Science and Technology (CNST@PoliMi), Istituto Italiano di Tecnologia, Milan 20133, Italy.
Electron Microscopy Facility, Istituto Italiano di Tecnologia, Via Morego 30, Genova 16163, Italy.
Chem Mater. 2021 Apr 13;33(7):2289-2297. doi: 10.1021/acs.chemmater.0c04097. Epub 2021 Mar 21.
Metal halide perovskites are attracting great interest for the fabrication of light-emitting devices encompassing light-emitting diodes, lasers, and scintillators. As the field develops, perovskite doping emerges as a promising way to enrich the material functionalities and enhance the luminescence yield and tunability. While Mn addition has been well explored, doping with lanthanides has received less attention, even though their intense and line-like luminescence is interesting for a wide range of applications. In this work, we study the doping of NMAPbBr layered perovskites with Eu and Eu tetrakis β-diketonate complex. By exploiting the antenna effect of the naphthalene-based functional cation (NMA = 1-naphtylmethylammonium), direct sensitization of Eu is obtained; nevertheless, it is not very efficient due to the non-optimal energy level alignment with the resonance acceptor level of the lanthanide. Protection of Eu in the form of tetrakis β-diketonate complex grants a more ideal coordination geometry and energetic landscape for the energy transfer to europium in the perovskite matrix, allowing for a nearly 30-fold improvement in luminescence yield. This work sets the basis for new synthetic strategies for the design of functional perovskite/lanthanide host-guest systems with improved luminescence properties.
金属卤化物钙钛矿在制造包括发光二极管、激光器和闪烁体在内的发光器件方面引起了极大的兴趣。随着该领域的发展，钙钛矿掺杂成为丰富材料功能、提高发光产率和可调谐性的一种有前途的方法。虽然锰的添加已得到充分研究，但镧系元素掺杂受到的关注较少，尽管它们强烈的线状发光在广泛的应用中很有吸引力。在这项工作中，我们研究了用铕和四（β-二酮）铕配合物对NMAPbBr层状钙钛矿进行掺杂。通过利用萘基功能阳离子（NMA = 1-萘甲基铵）的天线效应，实现了对铕的直接敏化；然而，由于与镧系元素的共振受体能级的能级排列不理想，其效率不是很高。以四（β-二酮）铕配合物形式对铕的保护为钙钛矿基质中向铕的能量转移提供了更理想的配位几何结构和能量格局，使发光产率提高了近30倍。这项工作为设计具有改进发光性能的功能性钙钛矿/镧系主客体系统的新合成策略奠定了基础。
