Single-Walled Carbon-Nanotubes-Based Organic Memory Structures.
The electrical behaviour of organic memory structures, based on single-walled carbon-nanotubes (SWCNTs), metal-insulator-semiconductor (MIS) and thin film transistor (TFT) structures, using poly(methyl methacrylate) (PMMA) as the gate dielectric, are reported. The drain and source electrodes were fabricated by evaporating 50 nm gold, and the gate electrode was made from 50 nm-evaporated aluminium on a clean glass substrate. Thin films of SWCNTs, embedded within the insulating layer, were used as the floating gate. SWCNTs-based memory devices exhibited clear hysteresis in their electrical characteristics (capacitance-voltage (C-V) for MIS structures, as well as output and transfer characteristics for transistors). Both structures were shown to produce reliable and large memory windows by virtue of high capacity and reduced charge leakage. The hysteresis in the output and transfer characteristics, the shifts in the threshold voltage of the transfer characteristics, and the flat-band voltage shift in the MIS structures were attributed to the charging and discharging of the SWCNTs floating gate. Under an appropriate gate bias (1 s pulses), the floating gate is charged and discharged, resulting in significant threshold voltage shifts. Pulses as low as 1 V resulted in clear write and erase states.
School of Electronic Engineering, Bangor University, Dean Street, Bangor LL57 1UT, UK. s.j.fakher@bangor.ac.uk.
Sundes
S
Fakher
Department of Electrical Engineering, United Arab Emirates University, Al Ain, UAE. r.radwan@uaeu.ac.ae.
Razan
R
Nejm
Department of Mathematics, Statistics and Physics, Qatar University, Doha, Qatar. ayesh@qu.edu.qa.
Ahmad
A
Ayesh
Masdar Institute, Abu Dhabi, UAE. aalghaferi@masdar.ac.ae.
Amal
A
Al-Ghaferi
School of Engineering and Computing Sciences, Durham University, Durham DH1 3LE, UK. d.a.zeze@durham.ac.uk.
Dagou
D
Zeze
School of Electronic Engineering, Bangor University, Dean Street, Bangor LL57 1UT, UK. m.f.mabrook@bangor.ac.uk.
Mohammed
M
Mabrook
D004566:Electrodes; D054802:Molecular Imprinting / Q000379:methods*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D019904:Polymethyl Methacrylate / Q000737:chemistry; D012666:Semiconductors
D037742:Nanotubes, Carbon; D019904:Polymethyl Methacrylate
charge transfer; organic memory devices; pentacene; single-walled carbon-nanotubes