Abstract: The surface plasmon resonance was excited by metallic grating introduced into the organic solar cells, which made absorption increasing. The absorption of PTB7∶ PC70BM organic solar cells were improved by different optimized metallic grating. In this paper,enhancement absorption rate on condition metallic grating with different shape were studied by finite element method, such as square grating, circular grating, eliptic grating, was placed at the bottom of the active layer. The result reveal that the square grating can make the total active layer absorption increased to 52. 9; from 29;,compared with the planar device. The enhancement absorption is most obvious. Next to the square grating, the eliptic grating improve to 49;. Circular grating has little effect on the absorption of the active layer, increased to 45;.

Key words: The surface plasmon resonance was excited by metallic grating introduced into the organic solar cells, which made absorption increasing. The absorption of PTB7∶ PC70BM organic solar cells were improved by different optimized metallic grating. In this paper,enhancement absorption rate on condition metallic grating with different shape were studied by finite element method, such as square grating, circular grating, eliptic grating, was placed at the bottom of the active layer. The result reveal that the square grating can make the total active layer absorption increased to 52. 9; from 29;,compared with the planar device. The enhancement absorption is most obvious. Next to the square grating, the eliptic grating improve to 49;. Circular grating has little effect on the absorption of the active layer, increased to 45;.