Multifunctional molybdenum disulfide flash memory using a PEDOT:PSS floating gate

Abstract

Two-dimensional transition metal dichalcogenide materials (TMDs), such as molybdenum disulfide (MoS2), have been considered promising candidates for future electronic applications owing to their electrical, mechanical, and optical properties. Here, we present a new concept for multifunctional MoS2 flash memory by combining a MoS2 channel with a PEDOT:PSS floating layer. The proposed MoS2 memory devices exhibit a switching ratio as high as 2.3\u2009×\u2009107, a large memory window (54.6\u2009±\u20097.80\u2009V), and high endurance (>1,000 cycles). As the PEDOT:PSS film enables a low-temperature solution-coating process and mechanical flexibility, the proposed P-memory can be embedded on a polyimide substrate over a rigid silicon substrate, offering high mechanical endurance (over 1,000 cycle bending test). Furthermore, both MoS2 and PEDOT:PSS have a bandgap that is desirable in optoelectronic memory operation, where charge carriers are stored differently in the floating gate depending on light illumination. As a new application that combines photodiodes and memory functions, we demonstrate multilevel memory programming based on light intensity and color. By combining the MoS2 channel with the PEDOT:PSS floating layer, a new concept device is proposed. This work demonstrates optoelectronic memory operation with high mechanical endurance through a 1,000-cycle bending test, which also offers multilevel memory programming operation based on light intensity and color.