First-Principles Study on Electronic Properties and Optical Spectra of Ce-Doped La2CaB10O19 Crystal
First-Principles Study on Electronic Properties and Optical Spectra of Ce-Doped La2CaB10O19 Crystal
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DOI：
10.1021/jp402706x
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发表时间：
2013-07
影响因子：
3.7
通讯作者：
Lixin Ning;Zong-Dong Wang;Yongfeng Wang;Junxian Liu;Shizhong Huang;C. Duan;Yongfan Zhang;Hongbin Liang
中科院分区：
文献类型：
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作者：
Lixin Ning;Zong-Dong Wang;Yongfeng Wang;Junxian Liu;Shizhong Huang;C. Duan;Yongfan Zhang;Hongbin Liang
本文分别采用混合密度泛函理论（DFT）和基于波函数的嵌入团簇计算，对La 2CaB 10 O 19（LCB）晶体中La 3+和Ca 2+位置取代的Ce 3+的电子性质和4f→5d跃迁进行了第一性原理研究。混合DFT与PBE 0功能产生的带隙为8.1 eV的LCB，在良好的协议与实验估计值为108.3 eV。计算结果表明，Ce ~（3+）~（4f）态与基质价带顶之间的能隙为1.93 ± 0.12 eV，与局域环境有一定的关系.基于CASSCF/CASPT 2水平上考虑自旋轨道效应的嵌入团簇计算结果，确定了与两个铈取代有关的实验观测激发带. Ce ~（3+）在两个掺杂位置上的4f→5d跃迁能量的差异可以用质心能量和晶场分裂的变化来解释。
We report herein a first-principles investigation on electronic properties and 4f→5d transitions of Ce3+ substituted at La3+ and Ca2+ sites of La2CaB10O19 (LCB) crystal, using the hybrid density functional theory (DFT) and the wave function-based embedded cluster calculations, respectively. The hybrid DFT with PBE0 functional yields a band gap of 8.1 eV for LCB, in good agreement with the experimentally estimated value of ∼8.3 eV. The energy gaps between the occupied Ce3+ 4f states and the valence band maximum of the host are predicted to be 1.93 ± 0.12 eV, with a slight dependence on the local environment. Based on the results of embedded cluster calculations at the CASSCF/CASPT2 level with the spin–orbit effect, the experimentally observed excitation bands are identified in association with the two cerium substitutions. The difference between the lowest 4f→5d transition energies of Ce3+ located at the two dopant sites are rationalized in terms of the variations in centroid energy and crystal-field split...