School of Materials Science and Nanotechnology, Jadavpur University, Kolkata, India.
J Phys Condens Matter. 2012 Jun 13;24(23):235501. doi: 10.1088/0953-8984/24/23/235501. Epub 2012 May 3.
An ab initio calculation has been carried out to investigate the biaxial strain ( - 10.71% < ε < 9.13%) effect on elastic, electronic and optical properties of CuAlO(2). All the elastic constants (c(11), c(12), c(13), c(33)) except c(44) decrease (increase) during tensile (compressive) strain. The band gap is found to decrease in the presence of tensile as well as compressive strain. The relative decrease of the band gap is asymmetric with respect to the sign of the strain. Significant differences between the parallel and perpendicular components of the dielectric constant and the optical properties have been observed due to anisotropic crystal structure. It is further noticed that these properties are easily tunable by strain. Importantly, the collective oscillation of the valence electrons has been identified for light polarized perpendicular to the c-axis. From calculations, it is clear that the tensile strain can enhance the hole mobility as well as the transparency of CuAlO(2).
我们进行了一项从头算研究，以考察双轴应变（-10.71%<ε<9.13%）对 CuAlO(2) 的弹性、电子和光学性质的影响。在拉伸（压缩）应变期间，所有弹性常数（c(11)、c(12)、c(13)、c(33)）除 c(44)外均减小（增大）。在拉伸和压缩应变的存在下，带隙被发现减小。带隙的相对减小对于应变的符号是不对称的。由于各向异性晶体结构，介电常数和光学性质的平行和垂直分量之间存在显著差异。进一步注意到，这些性质很容易通过应变进行调节。重要的是，已经识别出光垂直于 c 轴偏振时价电子的集体振荡。从计算结果可以清楚地看出，拉伸应变可以提高 CuAlO(2) 的空穴迁移率和透明度。
