中文摘要：

研究了980 nm激发下β-NaYF4：Yb3＋,Er3＋纳米片在不同温度下的上转换发光。在不同温度下,观察到了较强的绿色和红色上转换发光,分别对应于Er3＋的（2H11/2,4S3/2）→4I15/2和4F9/2→4I15/2能级跃迁。随着温度的升高,520 nm的绿色发光带和660 nm的红色发光带强度逐渐增大,545 nm的绿色发光带呈现出先增强（84～204 K）后减弱的趋势（204～483 K）。分析了样品上转换发光随温度变化的原因,并用三能级模型对样品的上转换发光随温度的变化规律进行了理论分析。

英文摘要：

Temperature dependent characteristics of upconversion luminescence in β-NaYF4 ： Yb3 ＋ , Er3＋ nanoplates under 980 nm excitation were reported. Intense green and red upconversion emissions corresponding to （2HH/2, 4S3/2 ） → 4Ii5/2 and 4F9/2→4115/2 transitions of the Er3＋ ions were observed, respectively. The green emission around 520 nm and the red emission around 660 nm continuously increase with increasing of temperature. The emission around 545 nm increases from 84 to 204 K and then decreases from 204 to 483 K. The temperature dependence of intensity characteristics was systematically analyzed by a simple three-level system.