PSL Research University, Chimie ParisTech - CNRS, Institut de Recherche de Chimie Paris, 75005 Paris, France.
Phys Chem Chem Phys. 2018 Sep 19;20(36):23294-23300. doi: 10.1039/c8cp03952f.
Wet-chemically synthesized inorganic materials often exhibit luminescence behavior. We have recently shown that the amorphous yttrium-aluminium-borate (a-YAB) powders obtained by sol-gel and modified Pechini methods exhibit organic impurities, responsible for their intense visible photoluminescence and phosphorescence afterglow. However, the heterogeneity of impurity organic compounds and difficulties in their intact extraction from the solid inorganic host matrix limit the extraction-based chemical analysis for luminophore identification. Here, we propose a photo-physical route based on time-gated triplet-state optical spectroscopy (TGTSS) to construct the electronic structures of the trapped unknown luminophores, which successfully illustrates the luminescence properties of a-YAB powders in more detail and also provides important insights intrinsic to the nature of the luminophores. The experimental results accompanied with TD-DFT calculations of the theoretical electronic structures thus help us to propose the probable luminophore compounds trapped in rigid a-YAB matrices. We anticipate that the present approach will open new opportunities for analyzing similar complex luminescent materials, including carbon dots, graphene oxides, etc., which is vital for their improvement.
湿化学合成的无机材料通常表现出发光行为。我们最近表明，溶胶-凝胶法和改进的皮切尼法获得的无定形钇铝硼酸盐（a-YAB）粉末存在有机杂质，这些杂质是其可见光致发光和磷光余晖强度的原因。然而，杂质有机化合物的不均匀性以及从固体无机主体基质中完整提取它们的困难限制了基于提取的化学分析来鉴定发光体。在这里，我们提出了一种基于时间门控三重态光学光谱（TGTSS）的光物理途径来构建被捕获的未知发光体的电子结构，该途径成功地更详细地说明了 a-YAB 粉末的发光特性，并且还为发光体的本质提供了重要的见解。实验结果伴随着理论电子结构的 TD-DFT 计算，从而帮助我们提出了可能被捕获在刚性 a-YAB 基质中的发光体化合物。我们预计，目前的方法将为分析类似的复杂发光材料（包括碳点、氧化石墨烯等）开辟新的机会，这对于它们的改进至关重要。
