presentation on GNR FET

1. Maruful Alam
Linun nahar tania

2. Content
 What is Graphene?
 History
 Evaluation of Graphene FET
 Advantages of Graphene
 What is GNR FET?
 Application of GNR FET
 Conclusion

3. WHAT IS GRAPHENE ?
 Graphene is the world’s first 2d crystal.
 Graphene is a thin layer of pure carbon and a
single tight packed layer of carbon atom
 It’s a single layer of hexagonal honeycomb
structure
 It’s thinnest known material only 1 atom
thick.
 Graphite itself consist of many graphene
sheets stacked together

4. HISTORY
 One of the very first patents pertaining to the production of graphene
was filed in October, 2002 entitled, "Nano-scaled Graphene Plates“.
 Two years later, in 2004 Andre Geim and Kostya Novoselov at
University of Manchester extracted single-atom-thick crystallites from
bulk graphite
 Geim and Novoselov received several awards for their pioneering
research on graphene, notably the 2010 Nobel Prize in Physics.

5. EVALOUTION OF GRAPHENE FET

6. Structure and evaluation of GNR
FET
 A 300-nm SiO2 layer underneath the graphene served as a back-gated
dielectric and a doped silicon substrate acted as the back-gate. Such
back-gate device have been very useful for proof-of-concept purpose,
but they suffer from unacceptably large parasitic capacitances and can
not be integrated with other components. Therefore practical GNR FET
need a top-gate.
 Schematics of different graphene MOSFET types: back-gated MOSFET
(left); top-gated MOSFET with a channel of exfoliated graphene or of
graphene grown on metal and transferred to a SiO2-covered Si wafer
(middle); top-gated MOSFET with an epitaxial-graphene channel
(right). The channel shown in red can consist of either large-area
graphene or graphene nanoribbons. b, Progress in graphene
MOSFET development compared with the evolution of nanotube FET.

7. ADVANTAGES OF GRAPHENE
 Higher electron mobility
 Superb electron & heat conductivity , grater than copper
 Stronger than diamond and steel
 Can be used to make anti bacterial materials as well as biodevices
 Very less break over voltage , less than 0.3 v

8. GRAPHENE NANORIBBON FET
 nanoribbons (also called nano-graphene
ribbons or nano-graphite ribbons), often
abbreviated GNRs, are strips
of graphene with ultra-thin width (<50 nm).
Graphene ribbons were introduced as a
theoretical model by Mitsutaka Fujita and
coauthors to examine the edge and nanoscale
size effect in graphene

9. GNR FET APPLICATIONS
 Room-Temperature High On/Off Ratio in Suspended GNRFET
 This work shows for the first time that ambipolar field effect characteristics and high on/off ratios at
room temperature can be achieved in relatively wide graphene nanoribbon (15 nm ~50 nm) by
controlled current annealing.
 we used controlled current annealing to create a narrow constriction in the suspended GNR to open a
confinement gap at room temperature.
 (AFM) was used to confirm the formation of a narrow constriction in the GNRs
 Fig.1. AFM images of typical FET devices consisting of a GNR contacted by Au electrodes before (a) and
after (b) suspending the GNR. (c) Line profile of the top section of the suspendedGNR.

10. Fig. 2. Electrical transport properties of a representative suspended GNR FET device
measured at room temperature, where the suspended GNR is 21±3 nm wide, ~1.4 nm
thick and ~600 nm long. (a) Transfer characteristic of the device after current annealing
to a predefined bias voltage set-point of 2.9 V. (b) I-V characteristics of the device
measured at various gate voltages ranging from -15 to 15 V. (c) Transfer characteristic
measured after various degrees of current annealing.(d) Current versus gate voltage (Vg)
measured at different bias voltages after the final stage of current annealing (annealed to
3.05 V).
15

11. GNRFET APPLICATION
 Current-voltage characteristics of a
graphene nanoribbon field-effect
transistor
 The operation of G-FETs is accompanied by the
formation of the lateral n-p-n (or p-n-p) junction
under the controlling (top) gate and the pertinent
energy barrier.
 The model can be used for the GNR-FET optimization.
FIG. 1: Schematic side (a) and top (b) views of a GNR-
FET structure.

12. Other applications:
 Others application are : #Graphene nanoribbon field-effect transistors
on wafer-scale epitaxial
 #Graphene nano-ribbon field-effect transistors as future low-power
devices
 #Device Performance of Graphene Nanoribbon Field-Effect Transistors
in the Presence of Line-Edge Roughness
 #Graphenenanoribbons could be a way to construct ballistic transistors

13. Conclusion
 High-power high frequency electronic devices
 Improved conductivity of materials
 Increasing the efficiency of electric batteries by use of
graphene powder
 Imaginary flexible cell phone
 screens will be thin as wallpaper that it could roll up
and take with you.
 GNR could easily remove salt from the water.

14. Referrence
 Room-Temperature High On/Off Ratio in Suspended Graphene
Nanoribbon Field EffectTransistors
Ming-Wei Lin1,*, Cheng Ling1,*, Yiyang Zhang1,2, Hyeun Joong Yoon2, Mark
Ming-Cheng
Cheng2, Luis A. Agapito3, Nicholas Kioussis3, Noppi Widjaja1, and Zhixian
Zhou1, a)
1Department of Physics and Astronomy, Wayne State University,
Detroit, MI 48201
2Department of Electrical and computer engineering, Wayne State
University,
Detroit, MI 48202
3Department of Physics, California State University, Northridge, CA 91330
http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=6629286&url=http%
3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D66
29286

15. Refference
Tunneling Current-Voltage Characteristics
ofGraphene Field-EfectTransistor
Victor Ryzhii1;3, Maxim Ryzhii1;3, and Taiichi Otsuji2;3
1Computer Solid State Physics Laboratory, University of
Aizu, Aizu-Wakamatsu, 965-8580, Japan
2 Research Institute for Electrical Communication,
Tohoku University, Sendai, 980-8577, Japan
3Japan Science and Technology Agency, CREST, Tokyo
107-0075, Japan
http://www.researchgate.net/publication/239005965