The recent demonstration of single-atom thick, sp3-hybridized group 14 analogues of graphene enables the creation of materials with electronic structures that are manipulated by the nature of the covalently bound substituents above and below the sheet. These analogues can be electronically derived from isolated (111) layers of the bulk diamond lattice. Here, we perform systematic Density Functional Theory calculations to understand how the band dispersions, effective masses, and band gaps change as the bulk silicon (111) layers are continuously separated from each other until they are electronically isolated, and then passivated with hydrogen. High-level calculations based on HSE06 hybrid functionals were performed on each endpoint to compare directly with experimental values. We find that the change in the electronic structure due to variations in the Si-H bond length, Si-Si-Si bond angle, and most significantly the Si-Si bond length can tune the nature of the band gap from indirect to direct with dramatic effects on the transport properties. First-principles calculations of the phonon-limited electron mobility predict a value of 464 cm2/Vs for relaxed indirect band gap Si-H monolayers at room temperature. However, for 1.6% tensile strain, the band gap becomes direct, which increases the mobility significantly (8 551 cm2/Vs at 4% tensile strain). In total, this analysis of Si-based monolayers suggests that strain can change the nature of the band gap from indirect to direct and increase the electron mobility more than 18-fold.

1.
A.
Kara
,
H.
Enriquez
,
A. P.
Seitsonen
,
L. C. L. Y.
Voon
,
S.
Vizzini
,
B.
Aufray
, and
H.
Oughaddou
,
Surf. Sci. Rep.
67
,
1
18
(
2012
).
2.
B.
Lalmi
,
H.
Oughaddou
,
H.
Enriquez
,
A.
Kara
,
S.
Vizzini
,
B.
Ealet
, and
B.
Aufray
,
Appl. Phys. Lett.
97
,
223109
(
2010
).
3.
A.
Fleurence
,
R.
Friedlein
,
T.
Ozaki
,
H.
Kawai
,
Y.
Wang
, and
Y.
Yamada-Takamura
,
Phys. Rev. Lett.
108
,
245501
(
2012
).
4.
P.
Vogt
,
P. D.
Padova
,
C.
Quaresima
,
J.
Avila
,
E.
Frantzeskakis
,
M. C.
Asensio
,
A.
Resta
,
B.
Ealet
, and
G. L.
Lay
,
Phys. Rev. Lett.
108
,
155501
(
2012
).
5.
M.
Fuentes-Cabrera
,
A.
Munoz
,
W.
Windl
,
A. A.
Demkov
, and
O. F.
Sankey
,
Modell. Simul. Mater. Sci. Eng.
7
,
929
938
(
1999
).
6.
L.
Chen
,
C.-C.
Liu
,
B.
Feng
,
X.
He
,
P.
Cheng
,
Z.
Ding
,
S.
Meng
,
Y.
Yao
, and
K.
Wu
,
Phys. Rev. Lett.
109
,
056804
(
2012
).
7.
A.
O'Hare
,
F. V.
Kusmartsev
, and
K. I.
Kugel
,
Nano Lett.
12
,
1045
1052
(
2012
).
8.
N. D.
Drummond
,
V.
Zólyomi
, and
V. I.
Fal'ko
,
Phys. Rev. B
85
,
075423
(
2012
).
9.
Z.
Ni
,
Q.
Liu
,
K.
Tang
,
J.
Zheng
,
J.
Zhou
,
R.
Qin
,
Z.
Gao
,
D.
Yu
, and
J.
Lu
,
Nano Lett.
12
,
113
118
(
2012
).
10.
L.
Stille
,
C. J.
Tabert
, and
E. J.
Nicol
,
Phys. Rev. B
86
,
195405
(
2012
).
11.
J. O.
Sofo
,
A. S.
Chaudhari
, and
G. D.
Barber
,
Phys. Rev. B
75
,
153401
(
2007
).
12.
D. C.
Elias
 et al.,
Science
323
,
610
613
(
2009
).
13.
L. C. L. Y.
Voon
,
E.
Sandberg
,
R. S.
Aga
, and
A. A.
Farajian
,
Appl. Phys. Lett.
97
,
163114
(
2010
).
14.
T. H.
Osborn
,
A. A.
Farajian
,
O. V.
Pupysheva
,
R. S.
Aga
, and
L. C. L. Y.
Voon
,
Chem. Phys. Lett.
511
,
101
105
(
2011
).
15.
J. C.
Garcia
,
D. B.
de Lima
,
L. V. C.
Assali
, and
J. F.
Justo
,
J. Phys. Chem. C
115
,
13242
13246
(
2011
).
16.
M.
Houssa
,
E.
Scalise
,
K.
Sankaran
,
G.
Pourtois
,
V. V.
Afanas'ev
, and
A.
Stesmans
,
Appl. Phys. Lett.
98
,
223107
(
2011
).
17.
Y.
Ding
and
Y.
Wang
,
Appl. Phys. Lett.
100
,
083102
(
2012
).
18.
K.
Chinnathambi
,
A.
Chakrabarti
,
A.
Banerjee
, and
S. K.
Deb
, e-print arXiv:org/abs/1205.5099v1.
19.
C. G.
Van de Walle
and
J. E.
Northrup
,
Phys. Rev. Lett.
70
,
1116
1119
(
1993
).
20.
N.
Gao
,
W. T.
Zheng
, and
Q.
Jinag
,
Phys. Chem. Chem. Phys.
14
,
257
261
(
2012
).
21.
Z.
Hajnal
,
G.
Vogg
,
L. J.-P.
Meyer
,
B.
Szucs
,
M. S.
Brandt
, and
T.
Frauenheim
,
Phys. Rev. B
64
,
033311
(
2001
).
22.
E.
Bianco
,
S.
Butler
,
S.
Jiang
,
Y.-H.
Liu
,
O. D.
Restrepo
,
W.
Windl
, and
J. E.
Goldberger
,
ACS Nano
7
(
5
),
4414
4421
(
2013
).
23.
J.
Qi
,
X.
Qian
,
L.
Qi
,
J.
Feng
,
D.
Shi
, and
J.
Li
,
Nano Lett.
12
,
1224
1228
(
2012
).
24.
G.
Kresse
and
J.
Hafner
,
Phys. Rev. B
47
,
558
561
(
1993
).
25.
G.
Kresse
and
J.
Hafner
,
Phys. Rev. B
49
,
14251
14269
(
1994
).
26.
P. E.
Blöchl
,
Phys. Rev. B
50
,
17953
17979
(
1994
).
27.
J. P.
Perdew
,
K.
Burke
, and
M.
Ernzerhof
,
Phys. Rev. Lett.
77
,
3865
3868
(
1996
).
28.
J. P.
Perdew
,
K.
Burke
, and
M.
Ernzerhof
,
Phys. Rev. Lett.
78
,
1396
(
1997
).
29.
J.
Heyd
,
G. E.
Scuseria
, and
M.
Ernzerhof
,
J. Chem. Phys.
118
,
8207
8215
(
2003
).
30.
J.
Heyd
,
G. E.
Scuseria
, and
M.
Ernzerhof
,
J. Chem. Phys.
124
,
219906
(
2006
).
31.
J.
Paier
,
M.
Marsman
,
K.
Hummer
,
G.
Kresse
,
I. C.
Gerber
, and
J. C.
Angyan
,
J. Chem. Phys.
124
,
154709
(
2006
).
32.
O. F.
Sankey
,
A. A.
Demkov
,
W.
Windl
,
J. H.
Fritsch
,
J. P.
Lewis
, and
M. A.
Fuentes-Cabrera
,
Int. J. Quantum Chem.
69
,
327
340
(
1998
).
33.
S. H.
Yang
,
Phys. Rev. B
58
(
4
),
1832
(
1998
).
34.
O. D.
Restrepo
,
K.
Varga
, and
S. T.
Pantelides
,
Appl. Phys. Lett.
94
,
212103
(
2009
).
35.
S.
Baroni
 et al., Quantum Espresso,
2010
, See http://www.pwscf.org/.
36.
G.
Nilsson
and
G.
Nelin
,
Phys. Rev. B
6
,
3777
3786
(
1972
).
37.
M.
Menon
,
E.
Richter
, and
K. R.
Subbaswamy
,
Phys. Rev. B
56
,
12290
12295
(
1997
).
38.
A. A.
Demkov
,
W.
Windl
, and
O. F.
Sankey
,
Phys. Rev. B
53
,
11288
11291
(
1996
).
39.
D.
Daisenberger
,
P. F.
McMillan
, and
M.
Wilson
,
Phys. Rev. B
82
,
214101
(
2010
).
40.
C.
Lee
,
X.
Wei
,
J. W.
Kysar
, and
J.
Hone
,
Science
321
,
385
388
(
2008
).
41.
K. S.
Kim
,
Y.
Zhao
,
H.
Jang
,
S. Y.
Lee
,
J. M.
Kim
,
K. S.
Kim
,
J.-H.
Ahn
,
P.
Kim
,
J.-Y.
Choi
, and
B. H.
Hong
,
Nature
457
,
706
710
(
2009
).
42.
M. R.
Falvo
,
G. J.
Clary
,
R. M.
Taylor
 II
,
V.
Chi
,
F. P.
Brooks
, Jr.
,
S.
Washburn
, and
R.
Superfine
,
Nature
389
,
582
584
(
1997
).
43.
C. A.
Marianetti
and
H. G.
Yevick
,
Phys. Rev. Lett.
105
,
245502
(
2010
).
44.
See supplementary material at http://dx.doi.org/10.1063/1.4860988 for silicane and graphene stress vs. strain curve with elastic instability. Also shown is the hexagonal Brillouin zone showing different M points.
45.
K. J.
Kuhn
,
IEEE Trans. Electron Devices
59
(
7
),
1813
1828
(
2012
).

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