单轴应变对BaHfO3电子结构与光学性质的调制影响

从第一性原理出发,在广义梯度近似(GGA)下,采用基于密度泛函理论的平面波超软赝势计算方法,着重研究了单轴应变对钙钛矿型陶瓷材料BaHfO3电子结构与光学性质的调制影响。研究结果表明:无应变作用时,BaHfO3是一种宽禁带绝缘体;施加单轴应变后其逐渐呈现半导体材料的特征。BaHfO3带隙随拉应变增加线性减小,压应变与带隙则具有明显的非线性关系。对光学性质的分析发现:施加压(拉)应变后,介电函数虚部尖峰增多(减小),光学吸收带边产生蓝移(红移)。此外,单轴应变作用下BaHfO3的静态介电常数和折射率均变大。上述研究表明施加单轴应变有效调制了BaHfO3的电子结构和光学性质,计算结果为应变BaHfO3光电材料的设计与应用提供了一定的理论依据。

Effect of the Uniaxial Strain on the Electronic Structures and Optical Properties of BaHfO3

Starting from first-principle within the generalized gradient approximation (GGA), the modulation impact of the uniaxial strain on the electronic structure and optical properties of perovskite-type ceramic material BaHfO3 has been investigated by the plane-wave pseudo-potential method based on the density function theory. The band structure analysis indicates that BaHfO3 is a wide band gap insulator in the case of without strain, while BaHfO3 gradually shows the characteristics of the semiconductor material under the uniaxial strain. Besides, the band gap of BaHfO3 linearly decreases with the tensile strain, and it appears obvious nonlinear relationship with the compressive strain. The optical properties calculations show that the spikes of the imaginary part of the dielectric function are increased (decreased) and the optical absorption band edge is blue-shifted (red-shifted) with the compressive (tensile) strain. Furthermore, the static dielectric constant and static refractive index of BaHfO3 under the uniaxial strain are increased. In a word, the involved results have shown that the uniaxial strain effectively modulates the electronic structure and optical properties of BaHfO3, which will provide a theoretical basis for the design and application of BaHfO3 optoelectronic materials.