A dual-mode vision sensor based on a ferroelectric Bi_xSm_2-xO₃ film for high-contrast imaging

Ferroelectric materials, owing to their unique optoelectronic effect and intrinsic polarization fields, are capable of accurately extract image features in outdoor lighting environments, which is highly challenging in machine vision systems. However, conventional ferroelectric-based vision sensors, confined to image sensing, incur latency and additional power consumption during data transmission. Here we report a dual-mode vision sensor based on a ferroelectric Bi_xSm_2-xO₃ film that achieves high-contrast imaging and storage functionalities. By strategically leveraging the photoelectric effect and the heat-sensitive characteristic of the ferroelectric polarization field, the polarization intensity of the ferroelectric film can be precisely modulated to achieve time-scale controllable photocurrent reversal, thereby significantly enhancing imaging contrast, while exploiting the non-volatile nature of the ferroelectric polarization to achieve an image storage functionality. The developed sensor array facilitates accurate extraction of target shape features, enabling high-contrast imaging in uneven light conditions. This integrated sensing-memory architecture establishes a new paradigm for robust machine vision systems operating in challenging environmental conditions.