Ferroelectric polarization-modulated two-dimensional homojunctions for enhanced nonvolatile multistate memory with self-powered optical readout capacity

Abstract

The advent of two-dimensional materials has paved the way for significant progress in homojunction technology, driving advancements in electronic and photonic devices while also unlocking new possibilities for next-generation technologies. Low-power programmable two-dimensional homojunctions represent a crucial direction for future development. Of particular interest among these novel homojunctions are ferroelectric polarization-modulated two-dimensional homojunctions, which hold promise for nonvolatile multistate memory with self-powered optical readout capacity, a unique feature rarely observed by others. This report presents a novel homojunction composed solely of two-dimensional materials and utilizes a double-top gate electrode structure to regulate the polarization state of the ferroelectric layer, thus programming the homojunction to achieve nine distinct states. This design not only provides a homojunction with non-volatile multistate storage capacity but also grants it a self-powered optical reading function. Notably, all the states can be read using a low optical power density of 660 nm light without the application of a bias voltage, and remain stable after being read 4350 times. The performance metrics are exceptional, featuring a maximum light/dark ratio of 2.1 × 10⁴, a specific detectivity of 3.87 × 10¹¹ Jones, and a retention capability of over 10³ seconds after several months. In a simulation of a memory array of 24 × 24 units, the nine storage states are nonvolatile and can be distinguished by optical readout. This innovative approach not only has potential for high-density data storage, but also provides an efficient method for self-powered optical readout, marking a significant leap forward in storage technology.