理学院学术报告—Giant Enhancement in Upconversion Luminescence of β-Ba2ScAlO5:Yb3+/Er3+ Phosphor by Intermediate Band through Ca2+ Doping

报告题目：Giant Enhancement in Upconversion Luminescence of β-Ba₂ScAlO₅:Yb³⁺/Er³⁺ Phosphor by Intermediate Band through Ca²⁺ Doping

报  告  人：胡俊山

报告时间：2023年06月08日 9:00

报告地点：6D-414

主办单位：理学院

报告人简介：

胡俊山，理学博士，2022年6月毕业于电子科技大学物理学专业；新加坡国立大学理学院，联合培养博士。研究方向主要包括稀土掺杂光致发光纳米材料、荧光粉、先进功能纳米材料和光电器件及其应用。发表SCI学术论文近30篇，以第一作者身份发表SCI学术论文10余篇；已授权国家发明专利三项；主持四川省自然科学基金面上项目一项，参与国家自然基金二项和四川省自然科学基金一项。

内容简介：

Luminescence intensity is a critical issue for upconversion oxides with high phonon energy. Herein, an effective enhancement in red upconversion luminescence (UCL) is implemented via an intermediate band (IB) in Ba₂ScAlO₅:Yb³⁺/Er³⁺ phosphor after Ca²⁺ doping. The down-shifting luminescence spectra under the irradiation of a 320 nm laser verify the existence of the IB. The physical mechanism is that the valence band (VB) → IB transition increases the absorption of excitation energy and provides plentiful electrons from the host to Er³⁺. Therefore, the red and green emission intensities are increased by 45.2 and 7.5 times, respectively. The dependence of luminescent intensity on power and an effective fluorescent lifetime of Ca²⁺ doped Ba₂ScAlO₅:Yb³⁺/Er³⁺ also confirms the proposed energy transfer mechanism. Based on the excellent red emission, the temperature-dependent luminescent properties of the title material are explored in the temperature range from 298 K to 358 K. The linear relationship between the luminescence and the temperature and the high sensitivity suggest the promising potential in biomedical temperature sensing applications. This work paves a new way for enhancing UCL and will arouse extensive interest in non-contact temperature sensing applications with single red upconversion emission.