Browsing by Author "Sahoo, Mamina"

Now showing 1 - 2 of 2

A Fluorographene-Based Synaptic Transistor
(2019-08-13)
Liu, Bo
;
Hong, Ming-Chun
;
Sahoo, Mamina
;
Ong, Bin Leong
;
Tok, Eng Soon
Exploring brain-inspired synaptic devices has recently become a new focus of research in nanoelectronic communities. In this emerging field, incorporating 2D materials into three-terminal synaptic transistors has brought various advantages. However, achieving a stable and long-term weight-modulation in these synaptic transistors, which are typically based on interface charge storage, is still a challenge due to the nature of their spontaneous relaxation. The application of an atomically thin fluorographene layer into the synaptic junction region suppresses this issue and improves the efficiency, tunability, and symmetry of the synaptic plasticity as well as establishing a stable weight-regulation paradigm. These unique properties can be attributed to the dipolar rotation of C-F in fluorographene. To obtain a better physical understanding, a vacancy-dependent C-F dipolar rotation model is proposed and supported by hysteresis analysis and density functional theory calculations. As proposed and demonstrated, the unique fluorographene-based synaptic transistor may be a promising building block for constructing efficient neuromorphic computing hardware.
Dimensionally anisotropic graphene with high mobility and a high on-off ratio in a three-terminal RRAM device
(2020-06-01)
Liu, Bo
;
Tai, Han Hsiang
;
Liang, Hanyuan
;
Zheng, En-Yan
;
Sahoo, Mamina
In the past decade, graphene has aroused worldwide academic passion in the electronics community, due to its unique two dimensional lattice structure and high mobility properties. Meanwhile, the utilization of graphene for next-generation nano-electronic materials is still under debate due to its intrinsic zero band gap nature. To meet the requirement of logic applications, diversified academic attempts have been carried out to modify its intrinsic band structure, such as doping, bilayer stacking, nano-patterning, or heterostructures. In this work, a tailor made strategy for graphene is proposed and experimentally demonstrated: a dimensionally anisotropic graphene based three terminal resistive random-access memory (RRAM). This device could be operated in two modes, which realized not only high carrier mobility (10(3) cm(2) V-1 s(-1)) and low gate leakage in field effect mode, but also a high on-off ratio (10(7)) and ultra-low off state current (1 pA) in resistive switching mode. This device also exhibits high reliability in logic data storage: long retention up to 8000 s, endurance of 400 DC operation cycles, and read immunity up to 1 million cycles. To guarantee the dimensional uniformity and high quality of the graphene, surface polishing and passivation techniques were carried out on Cu foil before graphene CVD synthesis. As demonstrated in this study, the current work paves the way for graphene toward practical logic and memory applications with high performance and low steady state power consumption.