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Supporting Information for Small, DOI: 10.1002/smll.201303696
Epitaxial Growth of Asymmetrically-Doped Bilayer Graphene for Photocurrent Generation Yu Zhou, Kai Yan, Di Wu, Shuli Zhao, Li Lin, Li Jin, Lei Liao, Huan Wang, Qiang Fu, Xinhe Bao, Hailin Peng*, and Zhongfan Liu*
Supporting information Epitaxial Growth of Asymmetrically-Doped Bilayer Graphene for Photocurrent Generation Yu Zhou1,†, Kai Yan1,†, Di Wu1, Shuli Zhao1, Li Lin1, Li Jin2, Lei Liao1, Huan Wang1, Qiang Fu2, Xinhe Bao2, Hailin Peng1,* and Zhongfan Liu1,* †
These authors contributed equally to this work.
1
Center for Nanochemistry, Beijing National Laboratory for Molecular Sciences (BNLMS),
State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering，Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, People’s Republic of China 2
State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy
of Sciences, Dalian 116023, China E-mail: [email protected]; [email protected]
Figure S1. Two-step growth procedure of asymmetrically doped bilayer graphene. (a) SEM image of discrete intrinsic monolayer graphene grains grown on copper foil with low CH4/H2 ratio. (b) SEM image of discrete intrinsic bilayer graphene grains grown on copper foil with high CH4/H2 ratio. Red arrows indicate the bilayer islands on the monolayer domains. Scale bars, 10 μm. f
25
Percent (%)
20 15 10 5 0 14.5
15.0
15.5
16.0
16.5
17.0
Angle ()
Figure S2. Analyses of layer number, stacking order, and crystalline registry of asymmetrically doped bilayer graphene. (a) Bright-field TEM image of asymmetrically doped bilayer graphene film. The intrinsic monolayer, intrinsic and nitrogen-doped bilayer regions are labeled by the black, blue and red circles, respectively. Scale bar: 1 μm. (b-e) Random normal incident SAED patterns of intrinsic and nitrogen-doped bilayer graphene taken from the location labeled in (a), respectively. In the every panel, intensity section and lattice angle along the diffraction pattern were plotted. (f) Histogram of angle distribution from 20 SAED patterns within the grain.
1000
600
2
-1 -1
Mobility (cm V s )
800
400 200 0 -3
-2
-1 0 1 12 -2 nG(10 cm )
2
3
Figure S3. Extraction of mobility of bilayer jucntion. Field-effect
motilities
were
extracted
from
the
transconductance,
gm,
as
follows,
L gm I L μ= ，where Cox is the gate capacitance per unit area, and L, W are the W CoxVds Vg WCoxVds
channel length and width , respectively. Cox=11.6 nF/cm2, L=3.8 µm, W=3.6 µm. The trend of mobility vs. carrier density in Figure S3 is affected by the contact resistance.
Supporting Information for Small, DOI: 10.1002/smll.201303696
Epitaxial Growth of Asymmetrically-Doped Bilayer Graphene for Photocurrent Generation Yu Zhou, Kai Yan, Di Wu, Shuli Zhao, Li Lin, Li Jin, Lei Liao, Huan Wang, Qiang Fu, Xinhe Bao, Hailin Peng*, and Zhongfan Liu*
Supporting information Epitaxial Growth of Asymmetrically-Doped Bilayer Graphene for Photocurrent Generation Yu Zhou1,†, Kai Yan1,†, Di Wu1, Shuli Zhao1, Li Lin1, Li Jin2, Lei Liao1, Huan Wang1, Qiang Fu2, Xinhe Bao2, Hailin Peng1,* and Zhongfan Liu1,* †
These authors contributed equally to this work.
1
Center for Nanochemistry, Beijing National Laboratory for Molecular Sciences (BNLMS),
State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering，Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, People’s Republic of China 2
State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy
of Sciences, Dalian 116023, China E-mail: [email protected]; [email protected]
Figure S1. Two-step growth procedure of asymmetrically doped bilayer graphene. (a) SEM image of discrete intrinsic monolayer graphene grains grown on copper foil with low CH4/H2 ratio. (b) SEM image of discrete intrinsic bilayer graphene grains grown on copper foil with high CH4/H2 ratio. Red arrows indicate the bilayer islands on the monolayer domains. Scale bars, 10 μm. f
25
Percent (%)
20 15 10 5 0 14.5
15.0
15.5
16.0
16.5
17.0
Angle ()
Figure S2. Analyses of layer number, stacking order, and crystalline registry of asymmetrically doped bilayer graphene. (a) Bright-field TEM image of asymmetrically doped bilayer graphene film. The intrinsic monolayer, intrinsic and nitrogen-doped bilayer regions are labeled by the black, blue and red circles, respectively. Scale bar: 1 μm. (b-e) Random normal incident SAED patterns of intrinsic and nitrogen-doped bilayer graphene taken from the location labeled in (a), respectively. In the every panel, intensity section and lattice angle along the diffraction pattern were plotted. (f) Histogram of angle distribution from 20 SAED patterns within the grain.
1000
600
2
-1 -1
Mobility (cm V s )
800
400 200 0 -3
-2
-1 0 1 12 -2 nG(10 cm )
2
3
Figure S3. Extraction of mobility of bilayer jucntion. Field-effect
motilities
were
extracted
from
the
transconductance,
gm,
as
follows,
L gm I L μ= ，where Cox is the gate capacitance per unit area, and L, W are the W CoxVds Vg WCoxVds
channel length and width , respectively. Cox=11.6 nF/cm2, L=3.8 µm, W=3.6 µm. The trend of mobility vs. carrier density in Figure S3 is affected by the contact resistance.
