Abstract β-NaGdF4:Yb3+,Er3+ upconversion (UC) particles were prepared by a facile hydrothermal process with assistance of citric acid (CA). The morphologies of β-NaGdF4 UC particles were controlled by changing the doses of CA in precursor. With an increase CA concentration in precursor, increase sizes of crystals were observed, resulting in the increasing of luminescence intensity. The energy transfer ET mechanism was analyzed in detail.

中文翻译：

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通过调节柠檬酸浓度对 β-NaGdF 4 :Yb 3+ ,Er 3+ 进行光谱管理和形态演化

摘要 β-NaGdF4:Yb3+,Er3+ 上转换（UC）粒子是在柠檬酸（CA）的辅助下通过简便的水热法制备的。β-NaGdF4 UC 颗粒的形态通过改变前体中 CA 的剂量来控制。随着前驱体中CA浓度的增加，观察到晶体尺寸增加，导致发光强度增加。详细分析了能量转移ET机制。