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Semiconductive
properties of metal nitrides.
(OVERVIEW)
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Conductive
atomic force microscopy on c-plane of ~5-20 nm InN nanocrystals
grown onto Si/Ta[100] substrates by 157 nm pulsed laser deposition
exhibit thermionic Schottky emission between the Pt/Ir tip and
the InN nanodomains and charge memory effects identified from
the hysteresis loop between forward and reverse I-V curves. The
effects are due to inhomogeneous electron distribution on the
surface of nanodomains and the electron confinement at the edges
of the boundaries that cause local modulation of the charge neutrality
and Fermi levels and put an upper limit of 4.7 eV at the electron
affinity of the c-plane.
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(a)
AFM image showing the morphology of an individual InN macrodomain
on the Si/Ta substrate (S).
(b) C-AFM image of (a) indicating ~5-20 nm wide conductive nanostructures.
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(c)
Double-sweeping where hysterysis of I-V curves is inicated (point
1 of image (e)).
(d) The same for point 2.
(e) Close C-AFM image indicates regions with high conductivity (white
coloured regions).
(f) Dependence between the logarithm of Schottky current and the
bias voltage of the tip for the 1 and 2 points of (e). The linear
response was obtained by fitting the thermionic Schottky emission
model to the experimental data.
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(a)
C-AFM image of InN nanodomains. The individual nanocrystals, might
be, (I) isolated (i.e. having no common boundaries. (II) Overlapped
(i.e. with common boundaries, point A, or (III) partially isolated
(i.e. with common boundaries with their neighbours only at certain
points, point B. The asymmetry of the peaks corresponds to overlapped
nanodomains.
(b) Current distribution following a scan along the line of (a)
for tip bias voltage . The distance between the points A and C
is ~14 nm.
(c) The linear dependence of the logarithm of the charge, induced
by the tip, and the size of the nanodomains for different bias
voltages of the tip.
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Relevant
Publications
- Schottky
and charge memory effects in InN nanodomains.
N. Spyropoulos-Antonakakis, E. Sarantopoulou, Z. Kollia, G. Drazic
and S. Kobe, Appl. Phys. Lett. 99(15), 153110 (2011).
DOI:10.1063/1.3651327
- Long-term
oxidization and phase transition of InN nanotextures.
E. Sarantopoulou, Z. Kollia, G. Drazic, S. and N. Spyropoulos-
Antonakakis,
Nanoscale Res. Lett. 6, 387 (2011).
DOI:
10.1186/1556-276X-6-387
Conference
Presentations
- Size
and quantum effects in InN nano-domains.
(INVITED)
E. Sarantopoulou, Z. Kollia and A.C. Cefalas,
Slonano 2010, Ljubljana, Slovenia, 20-22 October, 2010.
- The Role of Extended Defects
in Charge Accumulation at the Boundaries of AuN and InN Nanodomains.
N. Spyropoulos-Antonakakis, E. Sarantopoulou, Z. Kollia, A. C.
Cefalas,
International Conference on Extended Defects in Semiconductors
(EDS 2012),
Thessaloniki, Greece, 24-29 June, 2012.
- Charge memory effects in transition
metal nitride nanodomains.
E. Sarantopoulou, N. Spyropoulos Antonakakis, Z. Kollia
and A. C. Cefalas,
3rd International Nanotechnology Conference and Exhibition, NanoIsrael
2012,
Tel-Aviv, Israel, 26-27 March, 2012.
- Charge memory effects and confinement
in AuNx nanodomains,
N. Spyropoulos-Antonakakis, E. Sarantopoulou and Z. Kollia,
ICFSI 13, International Conference on the Formation of Semiconductor
Interfaces, , Prague, Czech Republic, 3-8 July 2011.
- Long
term oxidization and phase transition of InN epitaxial nanotextures.
E. Sarantopoulou, Z. Kollia, G. Drazic and
S. Kobe,
11th Trends in Nanotechnology International Conference, TNT 2010,
Braga, Portugal, 06-10 September, 2010.
- Epitaxial
InN/In2O3 -Ta and
InN-Si semiconducting nanotextures.
E. Sarantopoulou, Z. Kollia, A. C. Cefalas,
G. Drazic and S. Kobe,
6th International Conference on Nanosciences & Nanotechnologies
- NN09, Thessaloniki, Greece, July 13-15, 2009.
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48,
Vassileos Constantinou Aven. 11635 Athens, Greece
Tel: +30 210 7273840, Fax: +30 210 7273842, email :ccefalas@eie.gr
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