银纳米片等离子体效应增强有机太阳能电池及其性能优化研究

摘要

将银纳米片引入有机太阳能电池，增强了器件的光吸收及光电转换效率。制备得到了具有不同等离子共振吸收特性的银纳米片。当银纳米片的等离子共振吸收与活性层的吸收相匹配时，器件的光电流显著增强。通过改变银纳米片与活性层之间的距离，研究了等离子体共振增强电磁场的传递特性。两者的距离越近则耦合入活性层的电磁场越强，器件的光电流越高。经优化后，以P3HT∶PCBM为活性层的有机太阳能电池的光电转换效率由3.04%增长到3.82%，提高了26%。%Ag nanoprisms ( AgNPs) were introduced in polymer solar cells to improve the light ab-sorption and performance. By changing the size and morphology of AgNPs, different plasmonic reso-nance characteristics were obtained. The device with good spectral overlap between AgNPs SPRs and active layer exhibited the highest photocurrent. The influence of electromagnetic scattering by AgNPs in the polymer solar cell was further investigated by changing the thickness of PEDOT∶PSS buffer layer. It is found that more local electromagnetic near-fields couple to the photoactive layer with the decreasing of the thickness of PEDOT∶PSS layer. By optimizing the thickness of PEDOT∶PSS buffer layer and the spectral overlap between Ag nanoprisms and active layer, the power conversion effi-ciency of polymer solar cells with a structure of ITO/AgNPs/PEDOT∶PSS/P3 HT∶PCBM/LiF/Al is raised to 3. 82%, which is 1. 26 times than that of the control device without AgNPs layer.