南开大学李伟团队报道了单一卤化铅钙钛矿在可见光区实现近全光谱发射。相关研究成果发表在2024年7月16日出版的《德国应用化学》。

在具有全光谱发射的单一材料中实现可调光致发光（PL）工程是一个令人垂涎的目标，但也带来了巨大的挑战。

在此背景下，研究人员报道了通过高压处理在单组分二维（2D）混合卤化铅钙钛矿(ETA)₂PbBr₄ (ETA⁺ = (HO)(CH₂)₂NH³⁺)中实现跨越424至620nm可见光范围的近全光谱PL发射。压缩时发生压力诱导相变，将晶体结构从环境条件下的正交相转变为高压下的单斜相结构。

这种由有机胺阳离子的自适应和动态构型变化驱动的相变，能够有效和连续地缩小这种卤化物晶体中的带隙。无机层与有机胺阳离子（N-H…Br和O-H…Br氢键）之间的氢键相互作用有效地调节了有机胺阳离子的渗透和八面体畸变。因此，这种现象会引起相变，导致PL发射红移，从而导致近全光谱发射。

该项工作通过在单卤化物钙钛矿中采用高压，为实现覆盖可见光谱的宽PL发射开辟了可能性。

附：英文原文

Title: Near-Full-Spectrum Emission Realized in a Single Lead Halide Perovskite across the Visible-Light Region

Author: Lian-Cai An, Zi-Ying Li, Muhammad Azeem, Wei Li, Yan Qin, Fei-Fei Gao, Song-De Han, Guo-Ming Wang, Xian-He Bu

Issue&Volume: 2024-07-16

Abstract: The engineering of tunable photoluminescence (PL) in single materials with a full-spectrum emission represents a highly coveted objective but poses a formidable challenge. In this context, the realization of near-full-spectrum PL emission, spanning the visible light range from 424 to 620 nm, in a single-component two-dimensional (2D) hybrid lead halide perovskite, (ETA)2PbBr4 (ETA+ = (HO)(CH2)2NH3+), is reported, achieved through high-pressure treatment. A pressure-induced phase transition occurs upon compression, transforming the crystal structure from an orthorhombic phase under ambient conditions to a monoclinic structure at high pressure. This phase transition driven by the adaptive and dynamic configuration changes of organic amine cations enables an effective and continuous narrowing of the bandgap in this halide crystal. The hydrogen bonding interactions between inorganic layers and organic amine cations (N-H…Br and O-H…Br hydrogen bonds) efficiently modulate the organic amine cations penetration and the octahedral distortion. Consequently, this phenomenon induces a phase transition and results in red-shifted PL emissions, leading to the near-full-spectrum emission. This work opens a possibility for achieving wide PL emissions with coverage across the visible light spectrum by employing high pressure in single halide perovskites.

DOI: 10.1002/anie.202411298

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202411298