本文设计了一种球形串型二维表面等离子体光栅光吸收器,采用二维时域有限差分法(2D-FDTD)分析了该吸收器的几何结构参数对其吸收特性的影响.结果表明,通过调整小球的半径、球形串之间的中心距离以及球形串上小球的层数,可以有效地降低反射率,从而提高对光的吸收率.从中心位置向左右两边使球形串之间的中心距离线性减小,可明显改善其吸收效果.当球形串上小球的层数超过50层时,基本达到了饱和吸收的状态.这种光吸收器在薄膜太阳能电池中具有一定的应用前景.

A kind of 2D surface plasmon grating light absorber with spherical strings is designed in this paper. The effects of the geometrical parameters on the absorption characteristics are analyzed by using two-dimensional Finite-Difference Time-Domain (2 d-FDTD)method. Results show that,the reflectivity can be effectively reduced by adjusting the radius of the balls,the center distances between the spherical strings and the ball layers of the spherical strings,thus improving the absorption of light. Reducing the center distances between the spherical strings linearly from centre to the both sides,the absorption effect can be obviously improved. The absorption basically reaches saturation state when the ball layers of the spherical strings are more than 50 layers. The absorber has a certain application prospect in thin film solar cells.