Investigation of InS-InSe heterojunctions prepared using sulphurization of p-InSe
n-InS/p-InSe heterojunctions were obtained by annealing p-InSe samples in sulphur vapours. By means of the atomic force microscopy method, topology of InS film surface was investigated. Current-voltage characteristics of the heterojunction were measured, and principal mechanisms of charge transfer w...
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Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України
2012
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| Zitieren: | Investigation of InS-InSe heterojunctions prepared using sulphurization of p-InSe / Z.D. Kovalyuk, V.Y. Duplavyy, O.M. Sydor // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2012. — Т. 15, № 1. — С. 38-40. — Бібліогр.: 5 назв. — англ. |
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irk-123456789-1182492017-05-30T03:03:22Z Investigation of InS-InSe heterojunctions prepared using sulphurization of p-InSe Kovalyuk, Z.D. Duplavyy, V.Y. Sydor, O.M. n-InS/p-InSe heterojunctions were obtained by annealing p-InSe samples in sulphur vapours. By means of the atomic force microscopy method, topology of InS film surface was investigated. Current-voltage characteristics of the heterojunction were measured, and principal mechanisms of charge transfer were established. The spectrum of relative quantum efficiency of the heterojunction was measured. 2012 Article Investigation of InS-InSe heterojunctions prepared using sulphurization of p-InSe / Z.D. Kovalyuk, V.Y. Duplavyy, O.M. Sydor // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2012. — Т. 15, № 1. — С. 38-40. — Бібліогр.: 5 назв. — англ. 1560-8034 PACS 73.40.Lq http://dspace.nbuv.gov.ua/handle/123456789/118249 en Semiconductor Physics Quantum Electronics & Optoelectronics Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України |
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n-InS/p-InSe heterojunctions were obtained by annealing p-InSe samples in sulphur vapours. By means of the atomic force microscopy method, topology of InS film surface was investigated. Current-voltage characteristics of the heterojunction were measured, and principal mechanisms of charge transfer were established. The spectrum of relative quantum efficiency of the heterojunction was measured. |
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Kovalyuk, Z.D. Duplavyy, V.Y. Sydor, O.M. |
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Kovalyuk, Z.D. Duplavyy, V.Y. Sydor, O.M. Investigation of InS-InSe heterojunctions prepared using sulphurization of p-InSe Semiconductor Physics Quantum Electronics & Optoelectronics |
| author_facet |
Kovalyuk, Z.D. Duplavyy, V.Y. Sydor, O.M. |
| author_sort |
Kovalyuk, Z.D. |
| title |
Investigation of InS-InSe heterojunctions prepared using sulphurization of p-InSe |
| title_short |
Investigation of InS-InSe heterojunctions prepared using sulphurization of p-InSe |
| title_full |
Investigation of InS-InSe heterojunctions prepared using sulphurization of p-InSe |
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Investigation of InS-InSe heterojunctions prepared using sulphurization of p-InSe |
| title_full_unstemmed |
Investigation of InS-InSe heterojunctions prepared using sulphurization of p-InSe |
| title_sort |
investigation of ins-inse heterojunctions prepared using sulphurization of p-inse |
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Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України |
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2012 |
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http://dspace.nbuv.gov.ua/handle/123456789/118249 |
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Investigation of InS-InSe heterojunctions
prepared using sulphurization of p-InSe / Z.D. Kovalyuk, V.Y. Duplavyy, O.M. Sydor // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2012. — Т. 15, № 1. — С. 38-40. — Бібліогр.: 5 назв. — англ. |
| series |
Semiconductor Physics Quantum Electronics & Optoelectronics |
| work_keys_str_mv |
AT kovalyukzd investigationofinsinseheterojunctionspreparedusingsulphurizationofpinse AT duplavyyvy investigationofinsinseheterojunctionspreparedusingsulphurizationofpinse AT sydorom investigationofinsinseheterojunctionspreparedusingsulphurizationofpinse |
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2025-07-08T13:37:36Z |
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2025-07-08T13:37:36Z |
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1837086128461578240 |
| fulltext |
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2012. V. 15, N 1. P. 38-40.
PACS 73.40.Lq
Investigation of InS-InSe heterojunctions
prepared using sulphurization of p-InSe
Z.D. Kovalyuk, V.Y. Duplavyy and O.M. Sydor
Chernivtsi Department of the Institute of Materials Science Problems, NAS of Ukraine
5, Iryna Vilde str., 58001 Chernivtsi, Ukraine, Phone: 8 (0372) 52-00-50; e-mail: chimsp@ukrpost.ua
Abstract. n-InS/p-InSe heterojunctions were obtained by annealing p-InSe samples in
sulphur vapours. By means of the atomic force microscopy method, topology of InS film
surface was investigated. Current-voltage characteristics of the heterojunction were
measured, and principal mechanisms of charge transfer were established. The spectrum
of relative quantum efficiency of the heterojunction was measured.
Keywords: InS, InSe, heterojunction, current-voltage characteristic, annealing.
Manuscript received 12.12.11.; revised version received 16.01.12; accepted for
publication 26.01.12; published online 29.02.12.
1. Introduction
Semiconductor structures based on layered crystals are
of great interest because of the possibility to use them as
radiation-resistant photodevices [1]. There are some
ways to form heterojunctions based on InSe. As a result
of anisotropy of chemical bonds in layered crystals,
there is a possibility to obtain plane-parallel plates, the
surface of which contains a low density of dangling
bonds. The thickness of these plates can be several
micrometers thick, what enables to prepare
heterostructures (HS) by using the method of direct
optical contact [2]. Intrinsic oxide-InSe heterostructures
were prepared by annealing indium monoselenide
samples in presence of oxygen [3].
In [4] it was established a possibility for HS
preparation by a long-term (24…120 h) annealing in
sulphur vapours. The purpose of this paper is to
investigate the possibility to create n-InS/p-InSe HS by
sulphurization of p-InSe samples for 12 h. Like to that in
[4], we established that parameters of the structure
prepared on the basis of p-InSe are much better than in
the case of n-InSe, only p-type material being used as
substrates.
2. Experimental
Initial single crystals InSe were grown using the vertical
Bridgman method from a non-stoichiometric
composition In1.03Se0.97. To obtain p-type conductivity,
indium selenide was doped with Cd impurity. When its
content in the melt reaches 0.01%, the grown crystals
have the concentration of holes and their
mobility μ ≈ 80 cm
313cm10 −≈p
2/V·s at Т = 300 K.
Samples were cleaved from the ingot with a razor
blade. Samples for annealing were 0.8…1 mm thick and
2×5 mm in size.
The annealing was carried out in an evacuated
silica ampoule with InSe-substrates and crystalline
sulphur located in its opposite parts. The ampoule was
placed into the two-region furnace, the temperature in
the sulphur location was 550 K, and in the p-InSe
location – 465 K. Annealing time was equal to 12 h.
After the annealing, an n-InS film was formed on the
surface of InSe. After cleaving and cutting the samples,
the obtained HS were 5×5×0.1 mm in size.
For studying the surface topology, the atomic-force
microscopy (АFМ) method was used. It enabled to
obtain the data about the surface relief in the nanometer
scale. Measurements were carried out using the atomic-
force microscope Nanoscope IIIa Dimension 3000SPM
(Digital Instruments) in the tapping mode.
Current-voltage ( VI − ) characteristics were
measured using the “Solartron 1255” device, and an
analysis of the obtained dependences was made by
means of the program “СView 3.10”.
The photosensitivity spectra were measured at
room temperature using the monochromator
with the resolution 26 Å. The samples were illuminated
from the film’s side. All the spectra were normalized
with respect to the amount of incident photons.
2MDR −
3. Results and discussion
Fig. 1 shows three- (a) and two-dimensional (b) AFM
images of the obtained InS surface topology, which
shows that the surface of the film is formed by spherical
nanoobjects (75 nm in height and 100…200 nm in
diameter). Fig. 1c shows the distribution of heights of
nanograins over the lateral plane of thin film (along the
line in Fig. 1b).
© 2012, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
38
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2012. V. 15, N 1. P. 38-40.
a
b
c
Fig. 1. Three-dimensional (a) and two-dimensional (b) AFM
images of InS surface, (c) – distribution of nanograin heights
along the line of image (b).
In order to determine the change transport
mechanism through the heterojunctions under
consideration, the characteristics were measured
at forward and reverse biases. Fig. 2a shows forward
branches of the characteristics at various
temperatures in semilogarithm scale. The initial sections
of the characteristics at relatively low forward
biases are described by the expression
VI −
VI −
VI −
⎥
⎦
⎤
⎢
⎣
⎡
−⎟
⎠
⎞
⎜
⎝
⎛= 1exp
nkT
qVJJ s , (1)
where q is the elementary charge, T – temperature, k –
Boltzmann constant, n – diode ideality factor, V –
voltage, and Js – saturation current. At forward biases
V > 0.35 V, VI − characteristics deviate from the
expression (1).
The main reason of this deviation is the high series
resistance Rs of the substrate, as a result voltage mainly
drops on the series resistance. In order to take into
account the effect of the series resistance on the VI −
characteristics, they were plotted in coordinates lgJ vs
JRV s− . The values of Rs were determined by means of
extrapolation of the saturated segment of the Rdiff(V)
dependence within the temperature range from 253 to
332 K. Further, using these plots the diode factor n was
calculated using the expression
)ln/)(/( JVkTqn ΔΔ= . (2)
Within the temperature range 253 to 293 K, the diode
factor n is equal to 2.2, the current transport mechanism
in the space-charge region has a tunnel-recombination
nature, and at 332 K the over barrier emission is a
dominating current transport.
0 0.2 0.4 0.6 0.8 1.0
10 -5
10 -4
10 -3
n
3
=2.2
n
2
=2.2
n
1
=2.2
253 K
276 K
296 K
332 K
J,
Α
/cm
2
V, V
n
4
=1.8
a
0.1 1
10-6
10-5
10-4
10-3
m
1
=1.1
m
3
=1
m2=1
253 K
275 K
293 K
332 K
τ
Jτ
, Α
/cm
2
τVτ , V
m
4
=0.9
b
© 2012, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
Fig. 2. Forward (a) and reverse (b) branches of the current-
voltage characteristics of n-InS/p-InSe heterostructure at
various temperatures.
39
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2012. V. 15, N 1. P. 38-40.
1,0 1,5 2,0 2,5 3,0
0
0,2
0,4
0,6
0,8
1,0
η
, a
rb
. u
ni
ts
hν, eV
Fig. 3. Spectral dependence of the relative quantum efficiency
of photoconversion in the n-InS/p-InSe heterostructure.
The reverse branch of the characteristic is
governed by the power law. The exponential m (0.9…1)
is temperature independent due to the space charge
limited current mechanism.
VI −
The obtained spectra of relative quantum efficiency
of n-InS/p-InSe are characterized by a typical shape in
the case of heterojunctions. They are limited from both
shortwave (2.8 eV) and longwave (1.2 eV) regions
(Fig. 3).
4. Conclusion
The photosensitive HS InS-InSe was formed by means
of the annealing of InSe substrates in sulphur vapours
for 12 hours. The obtained thin films possessed the
nanoscale structure. The effect of the series resistance on
the characteristics was taken into account. The
tunnelling-recombination processes were established to
be the dominating current transport mechanism within
the temperature range from 253 to 294 K. The over
barrier emission is the dominating current mechanism at
332 K.
VI −
References
1. Z.D. Kovalyuk, V.N. Katerinchuk, O.A. Politanska,
O.N. Sydor and V.V. Homiak, Influence of γ-
irradiation on properties of InSe photodiodes //
Pis’ma zhurnal tekhnich. fiziki, 31(9), p. 1-6
(2005), in Russian.
2. V.L. Bakumenko, Z.D. Kovalyuk, L.N. Kurbatov,
V.G. Tagaev and V.F. Chishko, Investigation of
InSe-GaSe heterojunctions obtained by optical
contact // Fizika tekhnika poluprovodnikov, 14 (6),
p. 1115-1119 (1980), in Russian.
3. Z.D. Kovalyuk, O.N. Sydor, V.N. Katerynchuk and
V.V. Netyaga, Investigation of isotype
photosensitive (intrinsic oxide) n-InSe
heterostructures prepared by long-term thermal
oxidation // Fizika tekhnika poluprovodnikov, 41
(9), p. 1074-1077 (2007), in Russian.
4. Z.D. Kovalyuk, O.I. Kushnir, O.N. Sydor, and
V.V. Netyaga, Heterostructures manufactured by
annealing of InSe single crystals in sulphur vapours
// Tekhnologiya konstruirovaniye elektronnoi
apparatury, 79(1), p. 61-62 (2009), in Russian.
5. M. Lampert, P. Mark, Current Injection in Solids,
Academic Press, New York and London, 1970.
© 2012, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
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