Department of Materials Science, Faculty of Engineering, Kyushu Institute of Technology, 1-1 Sensui, Tobata, Kitakyushu 804-8550, Japan.
Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan.
Inorg Chem. 2023 Feb 6;62(5):2146-2152. doi: 10.1021/acs.inorgchem.2c03809. Epub 2023 Jan 26.
The single doping of Eu and codoping with Ga or La into perovskite (ABO)-type CaZrO and CaHfO were carried out to investigate the effect of codoping on the photoluminescence (PL) features of Eu, attempting the site-selective Eu doping at either A or B sites. To comprehend the Eu PL features, the accurate locations of Eu were examined by X-ray absorption near edge structure (XANES) and the proportions of Eu located at A or B sites (Eu(A) or Eu(B); Eu or Eu/Eu) were analyzed. No considerable differences in the XANES spectra and in the proportions of Eu(A) and Eu(B) were observed in the single-doped samples. On the other hand, the shape of the XANES spectra and the Eu proportion markedly differed in the codoped samples. Ga codoping (Ga/Ga) achieved Eu(A) proportions of more than 90%, and La codoping (La) resulted in the largest Eu(B) proportions of approximately 40%. In both PL and PL excitation spectra, the site-dependent spectral features were changed depending on the proportion of Eu(A) and Eu(B), especially the PL peaks at 595 nm were intensified most in the La codoped samples. Consequently, the site-dependent Eu PL features in CZO and CHO were found to become more conspicuous by the effect of Ga or La codoping. The results also revealed that the codoped ions work not only to compensate for the charge of aliovalent Eu but also to drive Eu to the intentional doping sites.
将 Eu 进行单掺杂以及 Ga 或 La 共掺杂到钙钛矿（ABO）型 CaZrO 和 CaHfO 中，以研究共掺杂对 Eu 光致发光（PL）特性的影响，尝试在 A 位或 B 位进行 Eu 的选择性掺杂。为了理解 Eu 的 PL 特性，通过 X 射线吸收近边结构（XANES）检查了 Eu 的精确位置，并分析了位于 A 位或 B 位（Eu(A)或 Eu(B)；Eu 或 Eu/Eu）的 Eu 比例。在单掺杂样品中，XANES 谱和 Eu(A)和 Eu(B)的比例没有明显差异。另一方面，共掺杂样品的 XANES 谱和 Eu 比例的形状明显不同。Ga 共掺杂（Ga/Ga）实现了超过 90%的 Eu(A)比例，而 La 共掺杂（La）导致了约 40%的最大 Eu(B)比例。在 PL 和 PL 激发光谱中，取决于 Eu(A)和 Eu(B)的比例，光谱特征呈现出明显的位依赖性，特别是在 La 共掺杂样品中，595nm 的 PL 峰得到了最大增强。因此，Ga 或 La 共掺杂的影响使得 CZO 和 CHO 中的 Eu 位依赖性 PL 特征变得更加明显。结果还表明，共掺杂离子不仅补偿了变价 Eu 的电荷，而且还将 Eu 驱动到了预期的掺杂位置。
