Bionic Scotopic-Adaptive Ternary CdS_<i>x</i>Se_1–<i>x</i> Memory Phototransistor for Weak RGB Light Perception

Bionic scotopic-adaptive phototransistors, inspired by the rod cells of the human retina, exhibit remarkable potential for enhancing the efficiency of vision systems in diverse applications, including security surveillance, medical imaging, and precision laser machining. Nonetheless, similar to their biological counterparts, these devices face a critical limitation: their scotopic-adaptive photoresponse struggles to comprehensively encompass the visible spectrum, impeding color differentiation under weak illumination. In this study, we present a bionic memory phototransistor (MPT) based on ternary CdSxSe1–x nanoribbons, which integrate the scotopic sensitivity of rods with the chromatic acuity of cones to enable RGB color discernment in weak-light conditions. The CdSxSe1–x nanoribbons synthesized in a selenium-rich atmosphere exhibit fewer chalcogen vacancies and a progressively reduced photoelectric storage window, confirming the pivotal role of these vacancies as surface oxygen adsorption sites forming a storage medium. By leveraging the charge storage accumulation effect and energy band engineering, we achieve weak light detection across the broad visible range of 300–725 nm, with a specific detectivity surpassing 1017 Jones. Through the synergistic operation of CdS0.30Se0.70, CdS0.58Se0.42, and CdS MPTs with tailored spectral properties, we accomplish detection and discrimination of weak RGB light at 200 nW·cm–2 under scotopic-adaptive modes. This integration of rod-inspired scotopic adaptation with cone-like chromatic discrimination offers an innovative design concept for the development of next-generation visual perception technologies.