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Graphene NanoMesh Field Effect Transistors (GNM-FETs). Presented by: Salim Berrada. What’s a GNM?. Elementary ribbon. W. Transistor Model. I D -V GS For all GNM at V DS =0,2V. I D -V G at V DS = 0.2V . Effective masses comparison. E G =553. E G =508. E G =268. - PowerPoint PPT Presentation
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1
Presented by:Salim Berrada
19/03/2013 Team Meeting
Graphene NanoMesh Field Effect Transistors (GNM-FETs)
http://computational-electronics.ief.u-psud.fr/
2
What’s a GNM?
W
Elementary ribbon
31/01/2013
http://computational-electronics.ief.u-psud.fr/
3
Transistor Model
31/01/2013
Undoped GNM Pristine G(ND = 1013 cm-2)
BN substrate
BN
source
gate
drainWy
Wx(a) (b)
xyUndoped GNM Pristine G
(ND = 1013 cm-2)
BN substrate
BN
source
gate
drainWy
Wx(a) (b)
xy
ID-VGS For all GNM at VDS=0,2V
10-1
100
101
102
103
104
-0.5 0 0.5 1 1.5
Cur
rent
(µA
/µm
)
Gate Voltage (V)
pristine
EG = 268 meV
EG = 508 meV
EG = 553 meV
VDS = 0.2 V
ID-VG at VDS = 0.2V
Effective masses comparison
EG=553EG=508EG=268
EG m*
268 0,064
508 0,074
268 0,113
GNM with EG=508meV
ID-VGS
0.1
1
10
100
1000
-0.5 0 0.5 1 1.5
VDS = 0.1 VVDS = 0.2 VVDS = 0.3 VVDS = 0.4 VD
rain
Cur
rent
(µA
/µm
)
Gate Voltage (V)
T = 300 K
100
1000
104
-0.5 0 0.5 1 1.5
VDS = 0.1 VVDS = 0.2 VVDS = 0.3 VVDS = 0.4 VD
rain
Cur
rent
(µA
/µm
)
Gate Voltage (V)
10 20 30 40 50 60Source-to-Drain Distance x (nm)
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
0.5
0.4
0.3
0.2
0.1
0
Ene
rgy
(eV
)
Ene
rgy
(eV
)
0 0.5 1 1.5 2Transmission Function
EfsEfd
10 20 30 40 50 60Source-to-Drain Distance x (nm)
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
0.5
0.4
0.3
0.2
0.1
0
Ene
rgy
(eV
)
Ene
rgy
(eV
)
0 0.5 1 1.5 2Transmission Function
10 20 30 40 50 6010 20 30 40 50 60Source-to-Drain Distance x (nm)
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
0.5
0.4
0.3
0.2
0.1
0
0.5
0.4
0.3
0.2
0.1
0
Ene
rgy
(eV
)
Ene
rgy
(eV
)
0 0.5 1 1.5 20 0.5 1 1.5 2Transmission Function
EfsEfd
10
100
1000
104
-0.5 0 0.5 1
Pristine Graphene ; V DS = 0.2V
Klein Tunneling
Thermionic
Total CurrentD
rain
Cur
rent
(µA
/µm
)
Gate Potential (V)
Contribution of Different Currents
Current Spectra at Dirac Point (VGS=0,2V) for VDS=0,2V
10-8 10-6 0.0001 0.01 1-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
Ndim = 12 ; EG = 508 meV ; V GS = 0.20
Vds = 0.3VVds = 0.4VVds = 0.2VVds = 0.1V
Current (µA/µm)
Ener
gy (e
V)
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0 100 200 300 400 500 600 700
Vds = 0.1vVds = 0.2VVds = 0.3VVds = 0.4V
Neu
tralit
y Po
int P
rofil
e (e
V)
Source-to-Drain Distance x(nm)
Results Analysis
Graphene Band structure
Dirac Point 0y yy
K QL
UGUSUD
Recall the band structure…
Qy= 0.02
UGUSUD
Qy= 0.04
UGUSUD
Comparision with Viet-Hung’s Code
APPENDIX
Pristine Graphene
Pristine Graphene ID-VGS
100
1000
104
-0.5 0 0.5 1 1.5
VDS = 0.1 VVDS = 0.2 VVDS = 0.3 VVDS = 0.4 VD
rain
Cur
rent
(µA
/µm
)
Gate Voltage (V)
Pristine Graphene: Currents Contrubution Analysis
10
100
1000
104
-0.5 0 0.5 1
Pristine Graphene ; V DS = 0.2V
Klein Tunneling
Thermionic
Total Current
Dra
in C
urre
nt (µ
A/µ
m)
Gate Potential (V)
101
102
103
104
-1 -0.5 0 0.5 1 1.5 2
Pristine Graphene ; V DS = 0.3V
Klein TunnelingThermoionicTotal current
Dra
in c
urre
nt (µ
A/µ
m)
Gate Volatge(V)
GNM 1 et 3
1
10
100
1000
-0.8 -0.4 0 0.4 0.8 1.2 1.6
Vds = 0.1VVds = 0.2V
Dra
in C
urre
nt(µ
A/µ
m)
Gate Voltage(V)
EG=268 meV
0.1
1
10
100
1000
-1.5 -1 -0.5 0 0.5 1 1.5 2
Vds = 0.1VVds = 0.2V
Dra
in C
urre
nt (µ
A/µ
m)
Gate Voltage (V)
EG=553 meV
