First-Principles Study on Structural, Electronic, and Spectroscopic Properties of 纬-Ca2SiO4:Ce3+ Phosphors

详细信息    查看全文

• 作者：Jun Wen ; Lixin Ning ; Chang-Kui Duan ; Shengbao Zhan ; Yucheng Huang ; Jie Zhang ; Min Yin
• 刊名：Journal of Physical Chemistry A
• 出版年：2015
• 出版时间：July 23, 2015
• 年：2015
• 卷：119
• 期：29
• 页码：8031-8039
• 全文大小：515K
• ISSN：1520-5215

文摘

In the present work, geometric structures, electronic properties, and 4f 鈫?5d transitions of 纬-Ca₂SiO₄:Ce³⁺ phosphors have been investigated by using first-principles calculations. Four categories of typical substitutions (i.e., the doping of the Ce³⁺ without the neighboring dopants/defects and with the neighboring V_O^{鈥⑩€?/sup>, Al_Si鈥? and V_Ca鈥? are taken into account to simulate local environments of the Ce3+ located at two crystallographically different calcium sites in the 纬-Ca₂SiO₄. Density functional theory (DFT) geometry optimization calculations are first performed on the constructed supercells to obtain the information about the local structures and preferred sites for the Ce3+. On the basis of the optimized crystal structures, the electronic properties of 纬-Ca₂SiO₄:Ce3+ phosphors are calculated with the Heyd鈥揝cuseria鈥揈rnzerhof screened hybrid functional, and the energies and relative oscillator strengths of the 4f 鈫?5d transitions of the Ce3+ are derived from the ab initio embedded cluster calculations at the CASSCF/CASPT2/RASSI-SO level. A satisfactory agreement with the available experimental results is thus achieved. Moreover, the relationships between the dopants/defects and the electronic as well as spectroscopic properties of 纬-Ca₂SiO₄:Ce3+ phosphors have been explored. Such information is vital, not least for the design of Ce3+-based phosphors for the white light-emitting diodes (w-LEDs) with excellent performance.}