In-Memory Sensing and Logic Processing in Negative Capacitance Phototransistors

Abstract

Nowadays, miniaturization, low power consumption and multi-scenario applications are urgent requirements for the development of the next generation of vision architecture. Eliminating the interface of image sensing, memory and digital processing units and folding the entire signal chain into one device has become a promising strategy but remains challenging. Here, a 2D fully ferroelectric-gated negative capacitance (NC) phototransistor is demonstrated to enable the integration of in-memory sensing and logic processing. Attributed to the combined action of ferroelectric NC effect and strong photogating effect, the prototype tungsten disulfide (WS₂) NC phototransistor exhibits a small subthreshold swing (SS) of 41.7 mV dec⁻¹ and high photodetectivity of 2.3 × 10¹³ Jones. The quick switching of conductance states illustrates that such a device is suitable for ultralow-power nonvolatile memory with high program/erase ratio (>10⁴), long retention time (>10⁴ s), stable cyclic endurance (>300 cycles) and ultralow programming energy (1.41 pJ/bit) and erasing energy (0.945 pJ/bit). The work demonstrates ferroelectric-optoelectronic engineering in 2D material to integrate sensing, memory, and logic all-in-one device, providing a promising implementation of vision system with low power consumption, low latency, and low system complexity.