Ultralow Current Switching in Flexible Hybrid PVP:MoS2/HfO x Bilayer Devices

We report an ultralow power consuming and forming-free hybrid flexible resistive random access memory device fabricated with poly(4-vinylphenol) (PVP):MoS2 composite and HfO x bilayer, exhibiting threshold switching with ultralow ON-current of 500 nA. While the higher concentration of MoS2 imparted the higher leakage current in the devices, the lower concentration devices exhibited decent switching with set and reset powers as low as 270 and 0.1 nW, respectively. The ultralow switching current indicates the formation of multiple weak nanosized conductive filaments created due to electromigration of Ag atoms under external bias. Moreover, heating temperature-dependent study of switching behavior confirms the metallic nature of the filament as the low resistance state (LRS) current falls significantly with rising temperature. Furthermore, these devices exhibited remarkable mechanical strength on flexible substrate with demonstration of nondestructive switching characteristics at a bending radius as low as 2.5 mm and after 100 consecutive compressive and tensile strain cycles at ±5-mm radius. The ultralow switching current with high flexibility indicates the capability of devices for advancement toward future low-power flexible memories and computing systems.