초록 |
We demonstrate that tunable plasmonic nanostructures prepared by layer-by-layer deposition of gold nanorods with various aspect ratios exhibit the significant enhancement of power conversion efficiency in poly(3-hexylthiophene):[6,6]-phenyl-C61 butyric acid methyl ester (P3HT:PCBM) bulk heterojunction solar cell. We present time-resolved photoluminescence (PL) studies of P3HT films coupled to controlled surface plasmons, as a means to understand how spectral plasmon positions affect exciton dynamics in active layer. We also find that the wavelength dependence of efficiency enhancement in P3HT:PCBM heterojunction solar cells correlates with contribution of fast relaxation dynamics in plasmon-exciton interaction, suggesting the dominant formation of hot exciton due to fast relaxation at high energy state. |