Photosynaptic transistor is considered to be a potential candidate for breaking the von Neumann bottleneck in photo‐communication field. Herein, a series of donor−acceptor type and crosslinked core−shell nanoparticles are designed and applied in phototransistors as a charge‐trapping electret. The outer shell is composed of poly(ethylene glycol) methyl ether methacrylate (PEGMA); while the inner core comprises donors of thiophene and bithiophene (2T) and acceptors of benzothiazole (BT), naphthalenediimide (NDI), and hexafluorobenzene‐naphthalenediimide (FB‐NDI). It is found that the core−shell and donor−acceptor design play an important role in the charge trapping, photoresponse, and the corresponding device performance. Accordingly, the phototransistor comprising the crosslinked core−shell nanoparticles with a donor of 2T and an acceptor of BT (PV2T‐BT) produced the highest memory ratio of 105 over 104 s at a high operating voltage of −40 V. Meanwhile, the same device presented the highest paired‐pulse facilitation ratio of 168% at a medium operating voltage of −1 V, and an ultra‐low energy consumption of 0.0324 fJ at a low operating voltage of −1 µV. The findings in this study provide a new perspective on material design for phototransistor devices. A series of donor−acceptor type and crosslinked poly(vinylthiophene)‐based core−shell nanoparticles are synthesized and applied in photosynaptic transistors as a charge‐trapping electret. Three kinds of acceptors are incorporated in the nanoparticles including benzothiazole, naphthalenediimide, and hexafluorobenzene−naphthalenediimide. Accordingly, the nanoparticles comprising bithiophene as a donor and benzothiazole as an acceptor present the best device performance with a high paired‐pulse facilitation (PPF) ratio of 168% at a low operating voltage of −1 V, and an ultra‐low energy consumption of 0.0324 fJ at an operating voltage of −1 µV.