Generally, Ag and N can be taken as relatively better candidates for p-type ZnO. In this letter, we investigate the electronic structures and optical properties of N- or Ag-doped ZnO with F as the reactive donor. F atom is found to not only enhance acceptor solubilities, but also lower acceptor levels in the band gap of co-doped ZnO. In addition, we analyze the imaginary portion of the dielectric functions, refractive indices, and loss functions for pure and co-doped ZnO. A comparison with pure ZnO shows that the remarkable feature for these co-doped ZnO is a strong absorption in the visible light region, indicating that they could be taken as the potential candidates for photocatalytic material.

当各向异性晶体介电主轴坐标系与入射光波所在平面坐标系取向不同时, 讨论折射光波场强E的问题变得比较复杂, 但是这种情形对于许多双轴晶体的非线性光学现象具有重要影响。在上述两坐标系任意取向的前提下, 讨论了平面波从各向同性介质入射到各向异性晶体后, 其折射光波电场强度E的大小和方向的一般表达式, 证明了折射光波电场强度的方向和大小可以通过求解一元四次方程和电磁场边界条件而得到。对于一些特殊的入射光波方向和具有特殊对称性的晶体, 折射光波电场强度E的方向与光波法线方向垂直, 也就此特殊情况进行了讨论。利用所得结果, 可以讨论两束折射光波能量的分配关系。