A careful design of the nanocrystal architecture can strongly enhance the nanocrystal function. So far, this strategy has faced a synthetic bottleneck in the case of refractory oxides. Here we demonstrate the epitaxial growth of hafnia shells onto zirconia cores and pure zirconia shells onto europium-doped zirconia cores. The core/shell structures are fully crystalline. Upon shelling, the optical properties of the europium dopant are dramatically improved (featuring a more uniform coordination and a longer photoluminescence lifetime), indicating the suppression of nonradiative pathways. These results launch the stable zirconium and hafnium oxide hosts as alternatives for the established NaYF₄ systems.

中文翻译：

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（掺铕）氧化锆和氧化铪的外延核/壳纳米晶体


纳米晶体结构的精心设计可以极大地增强纳米晶体的功能。到目前为止，该策略在难熔氧化物方面遇到了合成瓶颈。在这里，我们展示了氧化铪壳在氧化锆核上的外延生长以及纯氧化锆壳在掺铕氧化锆核上的外延生长。核/壳结构是完全结晶的。脱壳后，铕掺杂剂的光学性质显着改善（具有更均匀的配位和更长的光致发光寿命），表明非辐射途径受到抑制。这些结果推出了稳定的氧化锆和氧化铪主体作为已建立的 NaYF ₄ 系统的替代品。