Use of surface plasmons induced by plasmonic structures is a viable way for improving the performance of optoelectronic devices. Here, by employing block-copolymer lithography and nano-imprinting lithography, we demonstrate a highly effective multiple pattern of metal electrodes for organic photovoltaics, organic photodiodes and organic phototransistors. The surface plasmon effects of metal electrodes allow significant additional light absorption compared with metal electrodes without the multiple patterns, leading to remarkable enhancements in the performances.