Charge Transport in Single CuO Nanowires
Junnan Wu, Bo Yin, Fei Wu, Yoon Myung, and Parag Banerjee1)
Department of Mechanical Engineering and Materials Science, One Brookings Drive,
Washington University, St. Louis, Missouri – 63130, USA.
Supplementary Information S1
1.4x106
Temp = 260K
Current Density (A/m2)
1.2x106
1.0x106
8.0x105
6.0x105
5
4.0x10
Back-to-back
Schottky Model
2.0x105
Raw Data
0.0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Voltage (V)
As we state in our manuscript, we have fit the back to back Schottky model to our raw data.
The back to back Schottky model is given as1 –
J 01 J 02 sinh(
J (V ) 
J 01 exp(
qV
qV
)  J 02 exp(
)
2n01k BT
2n02 k BT
qB , B
2
1 2
where, J 01,02  A * T exp( k T )
B
1
qV
)
2k B T
Email: parag.banerjee@wustl.edu
1
The adjustable parameters used were φB1 and φB2 which are barrier heights for the two metalsemiconductor contacts, respectively and the ideality factors n01 and n02. A Matlab® code
was written to perform the fitting. The best-fit is obtained using the following values:
φB1= 0.6 eV; φB1= 0.352 eV; n01 = 1.053; n02 = 1.2
As noted in the fit, the back to back does not provide a good fit for the observed IV curve. On
the other hand, the space charge limited current fits are data much better as is shown in
Figure 1b. Therefore, we do not consider back to back Schottky as a possible mechanism for
charge conduction in the CuO nanowires.
2
Supplementary Information S2
4.0
3.5
3.0
=2

2.5
2.0
1.5
1.0
100
150
200
250 300
T (K)
350
400
Figure S.2. Plot of  versus temperature from 120 K – 400 K.  decreases with
temperature from 3.6 at 120 K to 1.26 at 400 K.  crosses over =2 at 250 K.
3
Supplementary Information S3
(a)
(b)
Figure S. 3 (a) O terminated CuO ( 1) plane. (b) Cu terminated CuO ( 1) plane. CuO is
monoclinic, (JCPDS no. 80-1916) and the dotted regions in both the diagrams represent a
single unit cell with dimensions in Å. The density of bonds on the two planes are
calculated to be 6.2  1014 cm-2 and 2.5  1015 cm-2, respectively. The planes exposed
 data shown in main text, Figure
 1a, inset.
are in line with the HRTEM
References for Supplementary Information:
1.
S. Sinha, S. K. Chatterjee, J. Ghosh and A. K. Meikap, J Appl Phys 113 (12) (2013).
4