of 6
S
1
Supplementary Information
1
2
Band Edge Tailoring in Few
-
layer Two
-
dimensional Molybdenum
3
Sulfides/Selenides Alloys
4
5
Yi
-
Rung Lin
1,2,3,4
, Wen
-
Hui Cheng
1,2
, Matthias
H.
Richter
2,
5
,
Joseph S. DuChene
1,2
,
Elizabeth A. Peterson
6,7
,
6
Cora
M.
Went
8
, Zakaria Y. Al
Balushi
1
,9
, Deep Jariwala
1
,#
,
Jeffrey B. Neaton
6,10,11
,
Li
-
Chyong Chen
3,4
and
7
Harry A. Atwater
1,2
,*
8
9
1
Thomas J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, California
10
91125 United States
11
2
Joint Center for Artificial
Photosynthesis, California Institute of Technology, Pasadena, California 91125
12
United States
13
3
Center
for Condensed Matter Sciences, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei,
14
10617, Taiwan
15
4
Center of Atomic Initiative for New
Materials, National Taiwan University, No. 1, Sec. 4, Roosevelt Road,
16
Taipei, 10617, Taiwan
17
5
Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125,
18
USA
19
6
Department of Physics, University of California, Berke
ley, California, 94720, USA
20
7
Joint Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory, Berkeley, California
21
94720, USA
22
8
Department of Physics, California Institute of Technology, Pasadena, CA 91125, USA
23
9
The
Resnick Sustainability
Institute
,
California Institute of Technology, Pasadena, California 91125
24
United States
25
10
Materials Science
Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720,
26
United States
27
11
Kavli Energy NanoSciences Institute
at Berkeley
, Berkeley, California 94720, USA
28
# Current address: Electrical and Systems Engineering, University of Pennsylvania
, Philadelphia, PA,
29
19104, USA
30
31
32
S
2
33
34
35
Figure S1
. Raman characterizations of MOCVD
-
grown MoS
2
on 4
-
inch
SiO
2
/Si substrate by using
36
514 nm line. The Raman spectra of different locations with various thicknesses on MoS
2
sample.
37
The 1L and 4L MoS
2
correspond to the location (b) and (c) position as shown in the Figure 1a.
38
39
40
41
42
S
3
43
44
Figure S
2
. Valence band and work function spectra measured by XPS. The intersection of two
45
lines indicates the valence band maximum of each sample
, which is relative to fermi level
(E
F
for
46
E
B
=0).
47
48
49
50
51
52
53
54
S
4
55
56
Figure S
3
. Extinction coefficient of different MoS
2(1
-
x
)
Se
2
x
samples. The dash lines indicate the
57
optical band gaps of each sample.
58
59
60
61
62
S
5
63
64
Figure S4.
(a
-
c) Simulated bond angles of pristine MoS
2
, MoSSe and MoSe
2
between various
65
bonds, such as S
-
S, Se
-
Se, and S
-
Se in small domain case (d) comparison of calculated bo
nd
66
angles in various compounds.
67
68
69
70
71
S
6
Table
S
1
.
All the chemical compositions of MoS
2(1
-
x)
Se
2x
in this work.
72
73
Averaged chemical compositions of MoS
2(1
-
x)
Se
2x
(with error bar)
Sample
x value
S
Se
MoS
2
0.01
0
2
0.0
1
0
MoS
1.76
0.01
Se
0.24
0.06
x=0.12
1.76
0.01
0.24
0.0
0
MoS
1.64
0.003
Se
0.36
0.04
x=0.18
1.64
0.0
5
0.36
0.0
1
MoS
1.54
0.04
Se
0.46
0.2
x=0.23
1.54
0.0
3
0.46
0.
05
MoS
1.48
0.03
Se
0.52
0.04
x=0.26
1.48
0.03
0.52
0.04
MoSe
2
0.1
x=1
0
2
0.
06
74