We report on the nonvolatile memory characteristics of a bistable organic memory (BOM) device with Au nanoparticles (NPs) embedded in a conducting poly(N-vinylcarbazole) (PVK) colloids hybrid layer deposited on flexible poly(ethyleneterephthalate) (PET) substrates. Transmission electron microscopy (TEM) images show the Au nanoparticles distributed isotropically around the surface of a PVK colloid. The average induced charge on Au nanoparticles, estimated using the C−V hysteresis curve, was large, as much as 5 holes/NP at a sweeping voltage of ±3 V. The maximum ON/OFF ratio of the current bistability in the BOM devices was as large as 1 × 105. The cycling endurance tests of the ON/OFF switching exhibited a high endurance of above 1.5 × 105 cycles, and a high ON/OFF ratio of ∼105 could be achieved consistently even after quite a long retention time of more than 1 × 106 s. To clarify the memory mechanism of the hole-mediated bistable organic memory device, the interactions between Au nanoparticles and poly(N...