The temperature-dependent electrical properties of Ag Schottky contacts to differently grown O-polar bulk ZnO single crystals were comparatively investigated in the temperature range of 100–300 K. Schottky contact to hydrothermal ZnO produced the higher barrier heights (lower ideality factors) than that of pressurized melt-grown ZnO. The modified Richardson plots for two samples produced the larger Richardson constant compared to the theoretical value of 32 A cm−2 K−2 for n-type ZnO, indicating that the inhomogeneous barrier height with the thermionic emission (TE) model could not explain the current transport. The conductive accumulation layers on the ZnO surfaces might not be removed effectively for two samples, which degraded the rectifying characteristics. The different electron transport characteristics between hydrothermal and pressurized melt-grown ZnO could be explained by the different degree of Ag-O formation at the interface.

References

References
1.
Kim
,
Y.-J.
,
Yoo
,
H.
,
Lee
,
C.-H.
,
Park
,
J. B.
,
Baek
,
H.
,
Kim
,
M.
, and
Yi
,
G.-C.
,
2012
, “
Position- and Morphology-Controlled ZnO Nanostructures Grown on Graphene Layers
,”
Adv. Mater.
,
24
, pp.
5565
5569
.10.1002/adma.201201966
2.
Um
,
H.-D.
,
Moiz
,
S. A.
,
Park
,
K.-T.
,
Jung
,
J.-Y.
,
Jee
,
S.-W.
,
Ahn
,
C. H.
,
Kim
,
D. C.
,
Cho
,
H. K.
,
Kim
,
D.-W.
, and
Lee
,
J.-H.
,
2011
, “
Recent Highly Selective Spectral Response With Enhanced Responsivity of n-ZnO/p-Si Radial Heterojunction Nanowire Photodiodes
,”
Appl. Phys. Lett.
,
98
, p.
033102
.10.1063/1.3543845
3.
Chung
,
S. Y.
,
Kim
,
S.
,
Lee
,
J.-H.
,
Kim
,
K.
,
Kim
,
S.-W.
,
Kang
,
C.-Y.
,
Yoon
,
S.-J.
, and
Kim
,
Y. S.
,
2012
, “
All-Solution-Processed Flexible Thin Film Piezoelectric Nanogenerator
,”
Adv. Mater.
,
24
(45), pp.
6022
6027
.10.1002/adma.201202708
4.
Avrutin
,
V.
,
Cantwell
,
G.
,
Zhang
,
J.
,
Song
,
J. J.
,
Silversmith
,
D. J.
, and
Morkoç
,
H.
,
2010
, “
Bulk ZnO: Current Status, Challenges, and Prospects
,”
Proc. IEEE
,
98
, pp.
1339
1350
.10.1109/JPROC.2010.2040363
5.
Oshima
,
E.
,
Ogino
,
H.
,
Niikura
,
I.
,
Maeda
,
K.
,
Sato
,
M.
,
Ito
,
M.
, and
Fukuda
,
T.
,
2004
, “
Growth of the 2-in-Size Bulk ZnO Single Crystals by the Hydrothermal Method
,”
J. Cryst. Growth
,
260
, pp.
166
170
.10.1016/j.jcrysgro.2003.08.019
6.
Nause
,
J.
, and
Nemeth
,
B.
,
2005
, “
Pressurized Melt Growth of ZnO Boules
,”
Semicond. Sci. Technol.
,
20
, pp.
S45
S48
.10.1088/0268-1242/20/4/005
7.
Lajn
,
A.
,
Wenckstern
,
H.
,
Zhang
,
Z.
,
Czekalla
,
C.
,
Biehne
,
G.
,
Lenzner
,
J.
,
Hochmuth
,
H.
,
Lorenz
,
M.
,
Grundmann
,
M.
,
Wickert
,
S.
,
Vogt
,
C.
, and
Denecke
,
R.
,
2009
, “
Properties of Reactively Sputtered Ag, Au, Pd, and Pt Schottky Contacts on n-Type ZnO
,”
J. Vac. Sci. Technol. B
,
27
, pp.
1769
1773
.10.1116/1.3086718
8.
Neville
,
R. C.
, and
Mead
,
C. A.
,
1970
, “
Surface Barriers on Zinc Oxide
,”
J. Appl. Phys.
,
41
, pp.
3795
3800
.10.1063/1.1659509
9.
Allen
,
M. W.
,
Durbin
,
S. M.
, and
Metson
,
J. B.
,
2007
, “
Silver Oxide Schottky Contacts on n-Type ZnO
,”
Appl. Phys. Lett.
,
91
, p.
053512
.10.1063/1.2768028
10.
Endo
,
H.
,
Sugibuchi
,
M.
,
Takahashi
,
K.
,
Goto
,
S.
,
Sugimura
,
S.
,
Hane
,
K.
, and
Kashiwaba
,
Y.
,
2007
, “
Schottky Ultraviolet Photodiode Using a ZnO Hydrothermally Grown Single Crystal Substrate
,”
Appl. Phys. Lett.
,
90
, p.
121906
.10.1063/1.2715100
11.
Coppa
,
B. J.
,
Fulton
,
C. C.
,
Kiesel
,
S. M.
,
Davis
,
R. F.
,
Pandarinath
,
C.
,
Burnette
,
J. E.
,
Nemanich
,
R. J.
, and
Smith
,
D. J.
,
2005
, “
Structural, Microstructural, and Electrical Properties of Gold Films and Schottky Contacts on Remote Plasma-Cleaned, n-type ZnO{0001} Surfaces
,”
J. Appl. Phys.
,
97
, p.
103517
.10.1063/1.1898436
12.
Kolkovsky
,
V.
,
Scheffler
,
L.
,
Hieckmann
,
E.
,
Lavrov
,
E. V.
, and
Weber
,
J.
,
2011
, “
Schottky Contacts on Differently Grown n-type ZnO Single Crystals
,”
Appl. Phys. Lett.
,
98
, p.
082104
.10.1063/1.3558728
13.
Kim
,
H.
, and
Kim
,
D.-W.
,
2010
, “
Silver Schottky Contacts to a-Plane Bulk ZnO
,”
J. Appl. Phys.
,
108
, p.
074514
.10.1063/1.3493261
14.
Wenckstern
,
H.
,
von Muller
,
S.
,
Biehne
,
G.
,
Hochmuth
,
H.
,
Lorenz
,
M.
, and
Grundmann
,
M.
,
2010
, “
Dielectric Passivation of ZnO-Based Schottky Diodes
,”
J. Electron. Mater.
,
39
, pp.
559
562
.10.1007/s11664-009-0974-1
15.
Schmidt
,
O.
,
Geis
,
A.
,
Kiesel
,
P.
,
Walle
,
C.
,
Johnson
,
N.
,
Bakin
,
A.
,
Wagg
,
A.
, and
Dohler
,
G.
,
2006
, “
Analysis of a Conducting Channel at the Native Zinc Oxide Surface
,”
Superlattices Microstruct.
,
39
, pp.
8
16
.10.1016/j.spmi.2005.08.056
16.
Rhoderick
,
E.
, and
Williams
,
R.
,
Metal-Semiconductor Contacts
,
2nd ed.
,
Oxford University Press
,
New York
.
17.
Kampen
,
T. U.
, and
Mönch
,
W.
,
1995
, “
Lead Contacts on Si(111):H-1×1 Surfaces
,”
Surf. Sci.
,
331–333
, pp.
490
495
.10.1016/0039-6028(95)00079-8
18.
Werner
,
J. H.
, and
Guttler
,
H. H.
,
1991
, “
Barrier Inhomogeneities at Schottky Contacts
,”
J. Appl. Phys.
,
69
, pp.
1522
1533
.10.1063/1.347243
19.
Farag
,
A. A. M.
,
Ashery
,
A.
,
Terra
,
F. S.
, and
Mahmoud
,
G. M.
,
2008
, “
Investigations of AlSb Thin Films Grown on Si by Liquid Phase Epitaxy
,”
J. Optoelectron. Adv. Matter.
,
10
, pp.
2713
2718
.
20.
Turut
,
A.
,
Saglam
,
M.
,
Efeoglu
,
H.
,
Yalcin
,
N.
,
Yildirim
,
M.
, and
Abay
,
B.
,
2005
, “
Interpreting the Nonideal Reverse Bias C-V Characteristics and Importance of the Dependence of Schottky Barrier Height on Applied Voltage
,”
Physica B
,
205
, pp.
41
50
.10.1016/0921-4526(94)00229-O
21.
Cheung
,
S. K.
, and
Cheung
,
N. W.
,
1986
, “
Extraction of Schottky Diode Parameters From Forward Current-Voltage Characteristics
,”
Appl. Phys. Lett.
,
49
, pp.
85
87
.10.1063/1.97359
22.
Chand
,
S.
, and
Kumar
,
J.
,
1996
, “
On the Existence of a Distribution of Barrier Heights in Pd2Si/Si Schottky Diodes
,”
J. Appl. Phys.
,
80
, pp.
288
294
.10.1063/1.362818
23.
Look
,
D.
,
Coskun
,
C.
,
Claflin
,
B.
, and
Farlow
,
G.
,
2003
, “
Electrical and Optical Properties of Defects and Impurities in ZnO
,”
Physica B
,
340–342
, pp.
32
38
.10.1016/j.physb.2003.09.188
24.
Osvald
,
J.
, and
Horvath
,
J., Js.
,
2004
, “
Theoretical Study of the Temperature Dependence of Electrical Characteristics of Schottky Diodes With an Inverse Near-Surface Layer
,”
Appl. Surf. Sci.
,
234
, pp.
349
354
.10.1016/j.apsusc.2004.05.046
25.
Chand
,
S.
, and
Kumar
,
J.
,
1996
, “
Evidence for the Double Distribution of Barrier Heights in Pd2Si/n-Si Schottky Diodes From I-V-T Measurements
,”
Semicond. Sci. Technol.
,
11
, pp.
1203
1208
.10.1088/0268-1242/11/8/015
26.
Forment
,
S.
,
Van Meirhaeghe
,
R. L.
,
De Vrieze
,
A.
,
Strubbe
,
K.
, and
Gomes
,
W. P.
,
2001
, “
A Comparative Study of Electrochemically Formed and Vacuum-Deposited n-GaAs/Au Schottky Barriers Using Ballistic Electron Emission Microscopy (BEEM)
,”
Semicond. Sci. Technol.
,
16
, pp.
975
981
.10.1088/0268-1242/16/12/305
27.
Kumar
,
A. A.
,
Janardhanam
,
V.
,
Reddy
,
V. R.
, and
Reddy
,
P. N.
,
2009
, “
Evaluation of Schottky Barrier Parameters of Pd/Pt Schottky Contacts on n-InP (100) in Wide Temperature Range
,”
Superlattices Microstruct.
,
45
, pp.
22
32
.10.1016/j.spmi.2008.10.016
28.
Osvald
,
J.
,
2006
, “
Intersecting Behaviour of Nanoscale Schottky Diodes I–V Curves
,”
Solid State Commun.
,
138
, pp.
39
42
.10.1016/j.ssc.2006.01.029
29.
Pakma
,
O.
,
Serin
,
N.
,
Serin
,
T.
, and
Altındal
,
Ş.
,
2008
, “
The Influence of Series Resistance and Interface States on Intersecting Behavior of I–V Characteristics of Al/TiO2/p-Si (MIS) Structures at Low Temperatures
,”
Semicond. Sci. Technol.
,
23
, p.
105014
.10.1088/0268-1242/23/10/105014
30.
Yu
,
L. S.
,
Liu
,
Q. Z.
,
Xing
,
Q. J.
,
Qiao
,
D. J.
,
Lau
,
S. S.
, and
Redwing
,
J.
,
1998
, “
The Role of the Tunneling Component in the Current–Voltage Characteristics of Metal-GaN Schottky Diodes
,”
J. Appl. Phys.
,
84
, pp.
2099
2104
.10.1063/1.368270
31.
Dong
,
Y.
,
Fang
,
Z.-Q.
,
Look
,
D. C.
,
Doutt
,
D. R.
,
Hetzer
,
M. J.
, and
Brillson
,
L. J.
,
2009
, “
Polarity-Related Asymmetry at ZnO Surfaces and Metal Interfaces
,”
J. Vac. Sci. Technol. B
,
27
, pp.
1710
1716
.10.1116/1.3119681
32.
Allen
,
M. W.
,
Alkaisi
,
M. M.
, and
Durbin
,
S. M.
,
2006
, “
Metal Schottky Diodes on Zn-Polar and O-Polar Bulk ZnO
,”
Appl. Phys. Lett.
,
89
, p.
103520
.10.1063/1.2346137
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