A photoactive memory is implemented on a n-type and p-type double-gate silicon nanowire (Si-NW) field-effect transistor (FET) through the grafting of solution-processable [6,6]-phenyl-C(61)-butyric acid methyl ester (PCBM) in nanogaps. Despite integration with organic material, superior FET characteristics are observed. Lowered operation voltage is achieved through the use of an optical source and an efficient photon-absorbing structure. Due to the naturally separated gate structure for PCBM embedment, moreover, memory performances stemming from a photoactive property are notably improved by biasing asymmetric voltage to the separated gates, which are individually controlled. The development of photoactive Si-NW FET based on CMOS process can pave the way of optoelectronic applications with more degree of freedom in terms of overall device design.