In this study, an organic memory structure having citrate-capped silicon nanoparticles (Si NPs) self-assembled on SiO2 layer is demonstrated to show memory charging effect. The Si NPs were prepared by a simple chemical oxidation and etching method with silicon powder. The hysteresis loops on C-V measurement were obtained by flatband voltage shifts, which demonstrate the presence of charge storages in the embedded pentacene capacitor of Si NPs. The formation of Si NPs and the citrate capping on the Si NPs were analyzed by high resolution transmission electron microscopy and Fourier transform infrared spectroscopy, respectively. With voltage sweep of +/- 10 V, a hysteresis loop having flatband voltage shift of 9.9 V was obtained. In addition, electrical performance measurement for the charge storage showed more than 10,000 s charge retention time. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3544488] All rights reserved.