In this paper, nanostructured thin films comprising wide-bandgap polyphenyl substituted naphthalene (TPPs) and dielectric polystyrene (PS) are prepared by a simple spin-coating method and employed as high-performance charge trapping layers in nonvolatile organic field-effect transistor (OFET) memory devices. Compared to the pure film counterparts, these nanostructured memory devices exhibit significant improvements in memory performance, both in terms of memory capacity and device stability. The best device demonstrates a 25% enhancement of the memory window (from 48 to 60 V) and a 3 orders of magnitude enhancement of the ON/OFF current ratio after 10⁴ s operation (from 1.7 × 10² to 2.8 × 10⁵). The most stable device achieves an ON/OFF current ratio of over 10⁴ when extrapolated to 28 years. This is mainly because the isolated charge trapping nanostructures and the interfacial dipole layer formed on the surface of the hybrid nanoarrays, which induce a small built-in electric field, effectively prohibit the leakage current.