Efficient charge storage media play a pivotal role in transistor‐based memories and thus are under intense research. In this work, the charge storage ability of type‐I InP/ZnS core/shell quantum dots is well revealed through studying a pentacene‐based organic transistor with the quantum dots (QDs) integrated. The quantum well‐like energy band structure enables the QDs to directly confine either holes or electrons in the core, signifying a dielectric layer‐free nonvolatile memory. Especially, the QDs in this device can be charged by electrons using light illumination as the exclusive method. The electron charging process is ascribed to the photoexcitation process in the InP‐core and the hot holes induced. The QDs layer demonstrates an electron storage density of ≈5.0 × 1011 cm−2 and a hole storage density of ≈6.4 × 1011 cm−2. Resultingly, the output device shows a fast response speed to gate voltage (10 µs), large memory window (42 V), good retention (>4.0 × 104 s), and reliable endurance. This work suggests that the core/shell quantum dot as a kind of charge storage medium is of great promise for optoelectronic memories.

All-inorganic perovskite cesium lead bromide (CsPbBr3) quantum dots (QDs) have been used as charge storage centers in floating-gate transistors. In this work, CsPbBr3 QDs are integrated into thin film transistors to create transistor-based memory. Unlike the floating-gate transistors previously reported, the CsPbBr3 QDs are placed between the dielectric and semiconductor layer, leading to direct contact with the semiconductor layer. Characterization of the device performance reveals that the CsPbBr3 QDs exhibit a strong tendency to store holes instead of electrons. Analysis unravels that this property possibly comes from the junction formed between the CsPbBr3 QDs and the transistor’s semiconductor layer, which can facilitate hole injection from the semiconductor layer to the QDs under a negative gate bias, as well as the storage of the injected holes in the QDs. Devices using an organic semiconductor (P3HT) or two-dimensional material (graphene) consistently verify this speculation. Benefiting from the hole storage ability of the CsPbBr3 QDs, these devices show a benign non-volatile memory feature. As transistor-based memories, these devices can be programmed by electricity and erased by electricity or light illumination, rendering them as capable of optoelectronic memory application. This work offers an alternative approach for novel transistor-based optoelectronic memory.