Photo-activated digital resistive switching in a cryogenic photomemory

Abstract Resistive switching is the basis of many emerging memory technologies. However, its operation at cryogenic temperatures remains scarce, and it generally lacks compatibility with optical control and in-situ electrical programmability. Here, we report the discovery of a photo-activated digital resistive switching effect in a cryogenic photomemory based on α-In 2 Se 3 . After an optical pulse, the device can be repeatably switched from a high- to a low-resistance state digitally, which persists long after the photoactivation. The switching threshold voltage can be continuously tuned over a wide range by the reset voltage pulse, additional optical pulses, and electrostatic gating, providing multimodal control over the memory logic. The device also exhibits a markedly enhanced photoresponse and resettable persistent photoconductivity, allowing the emulation of synaptic behaviors at cryogenic temperatures. Our work reveals a defect-mediated mechanism for embedding programmable digital logic into a nonvolatile photomemory, establishing a versatile platform for adaptive optoelectronics at cryogenic temperatures.