One-Transistor-One-Transistor (1T1T) Optoelectronic Nonvolatile MoS2 Memory Cell with Nondestructive Read-Out.

Abstract

Taking advantage of the superlative optoelectronic properties of single-layer MoS2, we developed a one-transistor-one-transistor (1T1T)-type MoS2 optoelectronic nonvolatile memory cell. The 1T1T memory cell consisted of a control transistor (CT) and a memory transistor (MT), in which the drain electrode of the MT was connected electrically to the gate electrode of the CT, whereas the source electrode of the CT was connected electrically to the gate electrode of the MT. Single-layer MoS2 films were utilized as the channel materials in both transistors, and gold nanoparticles acted as the floating gates in the MT. This 1T1T device architecture allowed for a nondestructive read-out operation in the memory because the writing (programming or erasing) and read-out processes were operated separately. The switching of the CT could be controlled by light illumination as well as the applied gate voltage due to the strong light absorption induced by the direct band gap of single-layer MoS2 (∼1.8 eV). The resulting MoS2 1T1T memory cell exhibited excellent memory performance, including a large programming/erasing current ratio (over 106), multilevel data storage (over 6 levels), cyclic endurance (200 cycles), and stable retention (103 s).