基于共轭聚合物给体材料P3HT和富勒烯衍生物受体材料PCBM共混的体异质结结构的聚合物太阳能电池，因其空穴载流子迁移率低而限制了P3HT：PCBM功能层厚度，从而影响了器件对入射光的吸收．在聚合物功能层表面引入微纳光栅结构可以使器件内电场重新分布并改善器件的光吸收．本文基于时域有限差分方法仿真得到了光栅周期为1μm，占空比为0．5以及入射波长分别为500和700nm时二维器件内光电场分布；并基于严格耦合波分析方法计算得到了不同光栅深度和光栅占空比的器件光吸收．理论分析表明：插入微纳光栅结构后，由于光栅衍射增强作用使器件内出现了光聚焦现象；当占空比为0．5时，光栅深度为10nm的器件在入射波长为512nm时，器件光学吸收增加了4．2％．基于聚二甲基硅氧烷的微压印技术，制备了微纳光栅结构聚合物太阳能，器件结构为ITO／PEDOT：PSS光栅层，P3HT：PCBM／LiF／Al．该器件与平板器件的性能对比实验证实，通过在PEDOT：PSS上引入微纳光栅结构，器件能量转化效率增加了31％．%The thickness of the active layer is limited by its low carrier mobility in the polymer solar cell composed of the blend bulk- heterojunction formed by P3HT as donor material and PCBM as acceptor material, which can affect the light absorption in the polymer solar cell. Nano-structure gratings inserted into polymer layer can redistribute the electrical field inside the device and improve its light absorption. Two-dimensional electrical field distributions inside the polymer solar cell are simulated with the grating period of 1 I.tm, fill ratio of 0.5 and incident wavelengths of 500 nm and 700 nm based on finite difference time domain. The light absorptions by the devices with different grating depths and fill ratios are calculated based on rigorous coupled wave. The analysis illustrates that light spots occur in the device due to the light diffraction caused by the gratings and the light absorption is increased by 4.2% with a grating fill ratio of 0.5, depth of 10 nm and an incident light wavelength of 512 nm. In experiment, nano-structure gratings are introduced into the devices by the micro-printing technology with PDMS and polymer solar cell is structured with ITO/PEDOT : PSS gratings/P3HT : PCBM/LiF/A1. The experimental results from the planar and the grating devices prove that the nano-structure gratings embedded in PEDOT : PSS layer increase the power conversion efficiency by 31%.
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