Investigation of non-volatile and photoelectric storage characteristics for MoS₂/h-BN/graphene heterojunction floating-gate transistor with the different tunneling layer thicknesses

The non-volatile memory devices based on traditional materials are unable to adapt to the background of the post-Moore era due to high energy consumption and low transmission speed. Therefore, the two-dimensional (2D) materials receive extensive attention on account of their excellent electrical and optical properties. The floating-gate transistors based on MoS₂/h-BN/graphene heterojunction possess excellent storage functions. In this paper, the characteristics of MoS₂/h-BN/graphene floating-gate transistors are investigated by manufacturing and comparing multiple devices. And the influences of the thickness of the h-BN tunneling layer on the storage functions are also explored. The device with the thickness of h-BN exceed 10 nm obtain the optimal non-volatile and photoelectric storage characteristics. Ultimately, the chosen floating-gate transistor can achieve switching ratio as high as ∼10⁵ at working voltages below 10 V, and also achieve multi-level storage by applying pulses of different amplitudes. And the device has very excellent durability and retention after 1000 cycles working. At the same time, the device also has perfect performance in the process of alternately applying electrical pulses and optical pulses, and finally achieves storage functions of electrical writing and optical erasing. These results prove that the outstanding non-volatile and photoelectric storage characteristics can be effectively achieved in 2D materials heterojunction floating-gate transistors. Therefore, the 2D materials floating-gate transistors will be potential candidate for post-Moore non-volatile memory chip.