Energy band gap and optical properties of lithium niobate from ab initio calculations
Energy band gap and optical properties of lithium niobate from ab initio calculations
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DOI：
10.1016/j.commatsci.2013.06.017
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发表时间：
2013-11-01
影响因子：
3.3
通讯作者：
Guilbert, L.
中科院分区：
文献类型：
--
作者：
Mamoun, S.;Merad, A. E.;Guilbert, L.
从第一性原理的广义梯度近似（GGA）计算了化学计量铌酸锂的电子和光学性质。带隙是稍微间接的。它的值被GGA低估了，在折射率的基础上使用我们的新方法，称为反向剪刀校正程序进行校正。修正后的值（4.9 eV）与以前用GW计算得到的值相当。在不同的剪刀修正下，重新计算了介电函数的频散，并与实验Sellmeier方程进行了比较。修正后的带隙在NIR-VIS-NUV范围内得到了很好的一致性。并估计了导价带极值处的跳变积分和有效质量。(C) 2013 Elsevier b.v.版权所有
The electronic and optical properties of stoichiometric lithium niobate are calculated from first principles within the Generalized Gradient Approximation (GGA). The band gap is found slightly indirect. Its value, underestimated by the GGA, is corrected on the basis of the refractive index by using our new approach called reverse scissor correction procedure. The corrected value (4.9 eV) is fairly comparable to previous ones obtained by GW calculation. The frequency dispersions of the dielectric function are re-calculated for different scissor corrections and compared to the experimental Sellmeier equation. A good agreement is obtained in the NIR-VIS-NUV range with our corrected band gap. The hopping integrals and effective masses at the extrema of the conduction and valence bands are also estimated. (C) 2013 Elsevier B. V. All rights reserved.