Using Light for Better Programming of Ferroelectric Devices: Optoelectronic MoS 2 ‐Pb(Zr,Ti)O 3 Memories with Improved On–Off Ratios

Abstract Ferroelectric (FE) devices are conventionally switched by an application of an electric field. However, the recent discoveries of light–matter interactions in heterostructures based on 2D semiconductors and FE materials open new opportunities for using light as an additional tool for device programming. Recently, a purely optical switching of FE polarization in heterostructures comprising 2D MoS 2 and FE oxide perovskites, such as BaTiO 3 and Pb(Zr,Ti)O 3 (PZT), was demonstrated. In this work, it is investigated whether this optical switching has a practical value and can be used to improve functional characteristics of MoS 2 ‐PZT FE field‐effect transistors for nonvolatile memory applications. It is demonstrated that the combined use of an electrical field and visible light improves the nonvolatile ON/OFF ratios in MoS 2 ‐PZT memories by several orders of magnitude compared to their purely electrical operation. The memories are read at zero gate voltage ( V G ) in darkness, but their ON and OFF currents, which routinely varied for different devices by over 10 5 , are achieved by programming at the same V G = −6 V with (ON state) and without (OFF state) light illumination, demonstrating its crucial importance. The light can likely serve as an important tool for better programming of a large variety of other semiconductor‐FE devices.