CAJ | 학술논문

基于密度泛函理论，采用第一性原理投影缀加波方法(PAW)，应用广义梯度近似(GGA)处理交换关联能，计算了正交CaTiO3块体材料的晶格参数、电子能带结构、态密度和光学性质。几何优化结果获得的晶格参数和原子坐标与已有的理论和实验数据很吻合。研究表明，正交CaTiO3是带隙为2.43 eV，价带顶和导带底都在Γ点的直接带隙半导体，价带顶和导带底主要由Ti-3d，O-2p态杂化而成。另外，计算了正交CaTiO3的吸收光谱，发现在波长较短的紫外光波段有一强烈吸收峰，基于能带和态密度分析了吸收光谱与电子跃迁间的关系，为正交CaTiO3的应用提供了理论依据。
기우밀도범함이론，채용제일성원리투영철가파방법(PAW)，응용엄의제도근사(GGA)처리교환관련능，계산료정교CaTiO3괴체재료적정격삼수、전자능대결구、태밀도화광학성질。궤하우화결과획득적정격삼수화원자좌표여이유적이론화실험수거흔문합。연구표명，정교CaTiO3시대극위2.43 eV，개대정화도대저도재Γ점적직접대극반도체，개대정화도대저주요유Ti-3d，O-2p태잡화이성。령외，계산료정교CaTiO3적흡수광보，발현재파장교단적자외광파단유일강렬흡수봉，기우능대화태밀도분석료흡수광보여전자약천간적관계，위정교CaTiO3적응용제공료이론의거。
Based on the density-functional theory,the structural parameters,electronic structure and optical properties of orthorhombic CaTiO3 have been studied by using the first principle projector-augmented wave (PAW) method and the generalized gradient approximation (GGA) treatment of exchange correlation energy. The calculated structural parameters of orthorhombic CaTiO3 coincide well with the experimental orthorhombic data. The energy band structure and density of states are obtained,which indicates that orthorhombic CaTiO3 is a direct gap semiconductor with a band gap of 2.43 eV at Γ (gamma) point. Furthermore,the absorption coefficient of orthorhombic CaTiO3 has been calculated,which shows that there is a strong absorption in UV light band. Based on the band structure and density of states,the mechanism of the optical transitions for orthorhombic CaTiO3 is explained,which provides a theoretical basis for application of orthorhombic CaTiO3.