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

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).