Probing PDMS/Single layer Graphene interaction using...
1
Experimental - Sample preparation Probing PDMS/Single layer Graphene interaction using optical spectroscopy L. Seremetis 1 , J. Parthenios 1 , O. Frank 3 , G. Konstantinidis 2 , G. Deligeorgis 2 , K. Novoselov 5 and C. Galiotis 1,4 , K. Papagelis 1,4 1 Institute of Chemical Engineering Sciences - Foundation of Research and Technology Hellas, 26504 Patras, Greece 2 Institute of Electronic Structure and Laser - Foundation of Research and Technology Hellas, 71110 Heraklion, Greece 3 J. Heyrovsky Institute of Physical Chemistry, v.v.i., Academy of Sciences of the Czech Republic, Prague, 8, 18223 Czech Republic 4 Materials Science Department, University of Patras, 26504, Greece 5 School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK Conclusions Ackowledgements: FORTH / ICE-HT acknowledges financial support from “Graphene Center Raman mapping of CVD grown graphene on PDMS Graphene on a 290nm Si/SiO2 substrate transferred from a SiO2/Si substrate to a second substrate (PMMA) Wet transfer on PDMS (1) 50x optical image of Graphene (2) 50x optical image of Graphene on PMMA (3) 100x optical image of Graphene on PDMS. [1] O. Frank, G. Tsoukleri, I. Riaz, K. Papagelis, J. Parthenios, A. C. Ferrari, A. K. Geim, K. S. Novoselov, and C. Galiotis, Nat Commun 2, 255 (2011). [2] O. Frank, G. Tsoukleri, J. Parthenios, K. Papagelis, I. Riaz, R. Jalil, K. S. Novoselov, and C. Galiotis, ACS Nano 4, 3131 (2010). [3] O. Frank, M. Mohr, J. Maultzsch, C. Thomsen, I. Riaz, R. Jalil, K. S. Novoselov, G. Tsoukleri, J. Parthenios, K. Papagelis, L. Kavan, and C. Galiotis, ACS Nano 5, 2231 (2011) [4] O. Frank, M. Bouša, I. Riaz, R. Jalil, K. S. Novoselov, G. Tsoukleri, J. Parthenios, L. Kavan, K. Papagelis, and C. Galiotis, Nano Lett. (2011). References Raman mapping of exfoliated graphene on PDMS Mechanical Exfoliation of graphite A wet Transfer Process to PDMS Chemical Vapor Deposition on Cu substrate 1 2 3 1200 1400 1600 2600 2800 Raman Shift (cm -1 ) Raman Intensity (arb. units) =514.5 nm PDMS PDMS 2D G 2 1 3 25 μm Cu foil H 2 CH 4 A B CVD process and the recipe Transferring process on PDMS A B PDMS Patterned PDMS substrate Circular well Other wells graphene Suspended graphene 9 10 11 12 13 14 15 16 1581 1582 1583 1584 <FWHM(G)> = 12.7 cm -1 <Pos(G)> = 1582.6 cm -1 Pos(G) (cm -1 ) FWHM(G)(cm -1 ) 1581 1582 1583 1584 2681 2682 2683 2684 2685 Pos(2D)/Pos(G) =0.7 Pos(2D) (cm -1 ) Pos(G) (cm -1 ) <Pos(G)> = 1582.6 cm -1 <Pos(2D)> = 2683.2 cm -1 22 23 24 25 26 27 2681 2682 2683 2684 2685 Pos(2D) (cm -1 ) FWHM(2D)(cm -1 ) <FWHM(2D)> = 23.7 cm -1 <Pos(2D)> = 2683.2 cm -1 1581 1582 1583 1584 8 9 10 11 12 13 14 15 <I2D/IG> = 10.9 I(2D/G) Pos(G) (cm -1 ) 1576 1578 1580 1582 1584 1586 2682 2684 2686 2688 2690 2692 2694 2696 2698 2700 supported suspended Pos(2D)/Pos(G) =-4.8 cm -1 Pos2D (cm -1 ) Pos(G) cm -1 <Pos(G)> = 1583.0 cm -1 <Pos(2D)> = 2691.0 cm -1 12 16 20 24 1576 1578 1580 1582 1584 1586 supported suspended Pos(G) (cm -1 ) FWHM(G)(cm -1 ) <Pos(G)> = 1583.0 cm -1 <FWHM(G)> = 16.5 cm -1 20 30 40 50 60 2682 2684 2686 2688 2690 2692 2694 2696 2698 2700 Pos(2D) (cm -1 ) FWHM(2D) (cm -1 ) <Pos(2D)> = 2691.0 cm -1 <FWHM(2D)> = 35.4 cm -1 1576 1578 1580 1582 1584 1586 0 2 4 6 8 10 supported suspended I2D/IG Pos(G) (cm -1 ) <I2D/IG> = 5.4 cm -1 <Pos(G)> = 1583.5 cm -1 1200 1500 1800 2100 2400 2700 3000 Raman Shift (cm -1 ) Raman Intensity (arb. units) PDMS PDMS SS 1 2D G =514.5 nm SS 2 SP 1 SP 2 Suspended graphene (SS) Supported graphene (SP) The dispersion of Pos(G) values is ~4 cm -1 The dispersion of Pos(2D) values is ~2 cm -1 The mean Pos(G) denotes that the flake is under a weak compression field The absence of D line and the high I2D/IG ratio denote the high quality of the single graphene crystal The dispersion of Pos(G) values is ~2 cm -1 The dispersion of Pos(2D) values is ~10 cm -1 The slope ΔPos(2D)/ΔPos(G) is NEGATIVE(!!) – Indication of Doping The ratio I2D/IG shows a huge dipersion from almost zero up to 10. This is a strong indication of an inhomogeneous doping on the transferred graphene. Suspended graphene retains doping levels as shown by the low values of the ratio I2D/IG Suspended graphene is under tension but it is difficult to estimate the strain due to the doping interference <Pos(2D)> ~ 2685 cm-1 <Pos(G)> ~ 1587 cm-1 Raman mapping of graphene/Cu prior to the transferring process Graphene is slightly compressed The ratio I2D/IG varies from 8-10 There is a maximum doping of 4.5x10 12 cm -2 imposed by the substrate Graphene transferring process is crucial for the quality of the single graphene layer in terms of the doping and strain distributions In CVD grown graphene transferred to PDMS, the doping imposed by the Cu substrate and the etchant is retained either supported or suspended
Transcript of Probing PDMS/Single layer Graphene interaction using...
Experimental - Sample preparation
Probing PDMS/Single layer Graphene interaction using optical spectroscopy
L. Seremetis1, J. Parthenios1, O. Frank3, G. Konstantinidis2, G. Deligeorgis2, K. Novoselov5 and C. Galiotis1,4, K.
Papagelis1,4
1Institute of Chemical Engineering Sciences - Foundation of Research and Technology Hellas, 26504 Patras, Greece2Institute of Electronic Structure and Laser - Foundation of Research and Technology Hellas, 71110 Heraklion, Greece
3J. Heyrovsky Institute of Physical Chemistry, v.v.i., Academy of Sciences of the Czech Republic, Prague, 8, 18223 Czech Republic4Materials Science Department, University of Patras, 26504, Greece
5School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK
Conclusions
Ackowledgements: FORTH / ICE-HT acknowledges financial support from “Graphene Center
Raman mapping of CVD grown graphene on PDMS
Graphene on a 290nm Si/SiO2 substratetransferred from a SiO2/Si substrateto a second substrate (PMMA)Wet transfer on PDMS
(1) 50x optical image of Graphene(2) 50x optical image of Graphene on PMMA(3) 100x optical image of Graphene on PDMS.
[1] O. Frank, G. Tsoukleri, I. Riaz, K. Papagelis, J. Parthenios, A. C. Ferrari, A. K. Geim, K. S. Novoselov, and C. Galiotis, Nat Commun 2, 255 (2011).[2] O. Frank, G. Tsoukleri, J. Parthenios, K. Papagelis, I. Riaz, R. Jalil, K. S. Novoselov, and C. Galiotis, ACS Nano 4, 3131 (2010).[3] O. Frank, M. Mohr, J. Maultzsch, C. Thomsen, I. Riaz, R. Jalil, K. S. Novoselov, G. Tsoukleri, J. Parthenios, K. Papagelis, L. Kavan, and C. Galiotis, ACS Nano 5, 2231 (2011)[4] O. Frank, M. Bouša, I. Riaz, R. Jalil, K. S. Novoselov, G. Tsoukleri, J. Parthenios, L. Kavan, K. Papagelis, and C. Galiotis, Nano Lett. (2011).
References
Raman mapping of exfoliated graphene on PDMS
Mechanical Exfoliation of graphiteA wet Transfer Process to PDMS
Chemical Vapor Deposition on Cu substrate
1 2 3
1200 1400 1600 2600 2800
Raman Shift (cm-1)
Ram
an I
nte
nsi
ty (
arb
. un
its)
=514.5 nm
PDMS PDMS
2D G
2
1
3
25 µm Cu foil
H2
CH4A
B
CVD process and the recipe Transferring process on PDMS
A B
PDMS
Patterned PDMS substrate
Circular well Other wellsgraphene Suspended
graphene
9 10 11 12 13 14 15 161581
1582
1583
1584
<FWHM(G)> = 12.7 cm-1
<Pos(G)> = 1582.6 cm-1
Po
s(G
) (c
m-1)
FWHM(G)(cm-1)
1581 1582 1583 15842681
2682
2683
2684
2685
Pos(2D)/Pos(G) =0.7
,
Po
s(2
D)
(cm
-1)
Pos(G) (cm-1)
<Pos(G)> = 1582.6 cm-1
<Pos(2D)> = 2683.2 cm-1
22 23 24 25 26 272681
2682
2683
2684
2685
Po
s(2
D)
(cm
-1)
FWHM(2D)(cm-1)
<FWHM(2D)> = 23.7 cm-1<Pos(2D)> = 2683.2 cm-1
1581 1582 1583 1584
8
9
10
11
12
13
14
15
<I2D/IG> = 10.9
I(2D
/G)
Pos(G) (cm-1)
1576 1578 1580 1582 1584 15862682
2684
2686
2688
2690
2692
2694
2696
2698
2700
supported suspended
Pos(2D)/Pos(G) =-4.8 cm-1
Po
s2D
(cm
-1)
Pos(G) cm-1
<Pos(G)> = 1583.0 cm-1
<Pos(2D)> = 2691.0 cm-1
12 16 20 241576
1578
1580
1582
1584
1586
supported suspended
Pos
(G)
(cm
-1)
FWHM(G)(cm-1)
<Pos(G)> = 1583.0 cm-1
<FWHM(G)> = 16.5 cm-1
20 30 40 50 602682
2684
2686
2688
2690
2692
2694
2696
2698
2700
Po
s(2
D)
(cm
-1)
FWHM(2D) (cm-1)
<Pos(2D)> = 2691.0 cm-1
<FWHM(2D)> = 35.4 cm-1
1576 1578 1580 1582 1584 15860
2
4
6
8
10
supported suspended
I2D
/IG
Pos(G) (cm-1)
<I2D/IG> = 5.4 cm-1
<Pos(G)> = 1583.5 cm-1
1200 1500 1800 2100 2400 2700 3000
Raman Shift (cm-1)
Ram
an I
nten
sity
(ar
b. u
nits
)
PDMS
PDMS
SS 1
2D G
=514.5 nm
SS 2
SP 1
SP 2
Suspended graphene (SS)
Supported graphene (SP)
The dispersion of Pos(G) values is ~4 cm-1
The dispersion of Pos(2D) values is ~2 cm-1
The mean Pos(G) denotes that the flake is under a weak compression fieldThe absence of D line and the high I2D/IG ratio denote the high quality of the single graphene crystal
The dispersion of Pos(G) values is ~2 cm-1
The dispersion of Pos(2D) values is ~10 cm-1
The slope ΔPos(2D)/ΔPos(G) is NEGATIVE(!!) – Indication of Doping The ratio I2D/IG shows a huge dipersion from almost zero up to 10. This is a strong indication of an inhomogeneous doping on the transferred graphene. Suspended graphene retains doping levels as shown by the low values of the ratio I2D/IGSuspended graphene is under tension but it is difficult to estimate the strain due to the doping interference
<Pos(2D)> ~ 2685 cm-1
<Pos(G)> ~ 1587 cm-1
Raman mapping of graphene/Cu prior to the transferring process
Graphene is slightly compressed
The ratio I2D/IG varies from 8-10
There is a maximum doping of 4.5x1012 cm-2 imposed by the substrate
Graphene transferring process is crucial for the quality of the single graphene layer in terms of the
doping and strain distributions
In CVD grown graphene transferred to PDMS, the doping imposed by the Cu substrate and the etchant
is retained either supported or suspended
