Grubbs Maegyn A, Gonzalez-Rodriguez Roberto, Dzyuba Sergei V, Janesko Benjamin G, Coffer Jeffery L
Department of Chemistry and Biochemistry, Texas Christian University, TCU Box 298860, Fort Worth, TX 76129, USA.
Department of Physics, University of North Texas, Denton, TX 76203, USA.
Nanomaterials (Basel). 2025 Jun 21;15(13):964. doi: 10.3390/nano15130964.
Ionic liquids (ILs) can ideally reduce defects and improve the film stability of emissive metal halide perovskite films. In this work, we measure how the structure and emission of methylammonium lead tribromide (MAPbBr) perovskite films is modulated by long alkyl chain-containing pyridinium, imidazolium, or pyrrolidinium ILs. Two different film deposition methods are compared, with the resultant films characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL) spectroscopy. For the latter, the differences in PL intensity of the perovskite are quantified using photoluminescence quantum efficiency (PLQE) measurements. It is found that a spin coating method in conjunction with the use of an imidazolium-containing IL (for a given precursor concentration) produces the strongest emissive perovskite. This optimal enhancement is attributed to a function of accessible surface charges associated with the heterocyclic cation of a given IL and perovskite defect passivation by bromide, the latter elucidated with the help of density functional theory. Proof-of-concept device fabrication is demonstrated for the case of a light emitting diode (LED) with the IL present in the emissive perovskite layer.
离子液体（ILs）理论上可以减少缺陷并提高发光金属卤化物钙钛矿薄膜的稳定性。在这项工作中，我们测量了含长烷基链的吡啶鎓、咪唑鎓或吡咯烷鎓离子液体如何调节三溴化甲铵铅（MAPbBr）钙钛矿薄膜的结构和发光。比较了两种不同的薄膜沉积方法，所得薄膜通过X射线衍射（XRD）、扫描电子显微镜（SEM）和光致发光（PL）光谱进行表征。对于后者，使用光致发光量子效率（PLQE）测量来量化钙钛矿PL强度的差异。发现旋涂法结合使用含咪唑鎓的离子液体（对于给定的前驱体浓度）可产生最强发光的钙钛矿。这种最佳增强归因于与给定离子液体的杂环阳离子相关的可及表面电荷的作用以及溴化物对钙钛矿缺陷的钝化，后者借助密度泛函理论得以阐明。对于发光钙钛矿层中存在离子液体的发光二极管（LED）情况，展示了概念验证器件的制造。
