CAJ | 학술논문

利用基于密度泛函理论框架下的平面波赝势法和广义梯度近似，计算分析Ca0.97Sr1.97AlO4F晶体结构的能带结构、态密度及电子密度差；采用价键理论研究Ca 0.97 Sr 1.97 AlO 4 F的共价性，并探讨Ce3+在Ca 0.97 Sr 1.97 AlO 4 F体系中的激发、发射光谱及荧光寿命。结果表明，价带主要由O、F原子的2p轨道构成，导带则主要由Al原子的2p轨道和Sr(1)和Sr(2)原子的4d轨道构成，能带间隙为6.235 eV；在Sr3AlO4F掺入Ca2+离子后，Ca/Sr(2)-O 和Ca/Sr(2)-F共价性明显增强；Ce3+离子在十配位的Sr(1)O 8 F 2和八配位的Sr(2)O 6 F 2格位中的发射主峰分别约为472和550 nm，荧光寿命(τ1/e )分别为38.35和49.45 ns。
이용기우밀도범함이론광가하적평면파안세법화엄의제도근사，계산분석Ca0.97Sr1.97AlO4F정체결구적능대결구、태밀도급전자밀도차；채용개건이론연구Ca 0.97 Sr 1.97 AlO 4 F적공개성，병탐토Ce3+재Ca 0.97 Sr 1.97 AlO 4 F체계중적격발、발사광보급형광수명。결과표명，개대주요유O、F원자적2p궤도구성，도대칙주요유Al원자적2p궤도화Sr(1)화Sr(2)원자적4d궤도구성，능대간극위6.235 eV；재Sr3AlO4F참입Ca2+리자후，Ca/Sr(2)-O 화Ca/Sr(2)-F공개성명현증강；Ce3+리자재십배위적Sr(1)O 8 F 2화팔배위적Sr(2)O 6 F 2격위중적발사주봉분별약위472화550 nm，형광수명(τ1/e )분별위38.35화49.45 ns。
The energy band structure, density of states and electronic density difference of Ca0.97Sr1.97AlO4F were calculated using the planewave pseudopotential method based on density function theory and generalized gradient approximation. The covalence of Ca0.97Sr1.97AlO4F was studied with valence bond theory. The excitation and emission spectra and fluorescent lifetimes of Ca0.97Sr1.97AlO4F doped with Ce3+ were investigated. The results show that the valence band is mostly composed of O and F 2p orbital, while the conduction band is mainly constructed from the Sr(1), Sr(2) atoms 4d and Al atoms 2p orbits, the energy gap is 6.235 eV. The bond covalence of Ca/Sr(2)-O and Ca/Sr(2)-F is strengthened with increasing the concentration of Ca2+in Sr 3 AlO 4 F host. The emission peaks and fluorescence lifetime (τ1/e) of Ce3+ in both two sites of 10-fold oxy-fluoride coordination (Sr(1)O8F2) and 8-fold coordination (SrO6F2) are about 472 nm, 38.35 ns and 550 nm, 49.45 ns, respectively.