Programming/erasing efficiency of charge transfer photomemory

Optically controlled non-volatile memory devices represent a promising paradigm for next-generation data storage, offering advantages such as high-speed, non-contact operation, and robust immunity to electromagnetic interference. In this study, an organic photomemory device with excellent photo-switching capabilities was fabricated using polyimide thin films. The resistive switching mechanism is attributed to a reversible molecular transformation between insulating aromatic and conductive quinoid moieties. Under UVA irradiation, the device transitions from a high resistance state (HRS) to a low resistance state in an ultrafast “Write” operation, inducing a current increase of over eight orders of magnitude (from ∼10−12 to ∼10−3 A). Conversely, a targeted UVC irradiation for ∼25 s executes the “Erase” operation, restoring the HRS. To address the inherent temporal asymmetry between these processes, an optimized wavelength-selective strategy is proposed, utilizing the UVA band for programming and the UVC band for erasing. This dual-band approach effectively mitigates spectral crosstalk, significantly enhancing the device’s operational efficiency, contrast, and cyclic stability, while maintaining a robust data retention of ∼14 000 s.