Electrical properties of fast cooled InSe single crystals
Influence of fast cooling on electrical properties of n-InSe single crystals is investigated for an ingot grown by the Bridgman method. Electrical characteristics and their anisotropy are investigated in the temperature range 80 to 410 K. It is found that fast cooling, as soon as crystallization...
Gespeichert in:
| Datum: | 2008 |
|---|---|
| Hauptverfasser: | , , , |
| Format: | Artikel |
| Sprache: | English |
| Veröffentlicht: |
Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України
2008
|
| Schriftenreihe: | Semiconductor Physics Quantum Electronics & Optoelectronics |
| Online Zugang: | http://dspace.nbuv.gov.ua/handle/123456789/118664 |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Zitieren: | Electrical properties of fast cooled InSe single crystals / A.V. Zaslonkin, Z.D. Kovalyuk, I.V. Mintyanskii, P.I. Savitskii // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2008. — Т. 11, № 1. — С. 54-58. — Бібліогр.: 17 назв. — англ. |
Institution
Digital Library of Periodicals of National Academy of Sciences of Ukraine| id |
irk-123456789-118664 |
|---|---|
| record_format |
dspace |
| spelling |
irk-123456789-1186642017-05-31T03:10:38Z Electrical properties of fast cooled InSe single crystals Zaslonkin, A.V. Kovalyuk, Z.D. Mintyanskii, I.V. Savitskii, P.I. Influence of fast cooling on electrical properties of n-InSe single crystals is investigated for an ingot grown by the Bridgman method. Electrical characteristics and their anisotropy are investigated in the temperature range 80 to 410 K. It is found that fast cooling, as soon as crystallization is completed, of the ingot leads to an increase of the free electron concentration, conductivity along layers, and conductivity anisotropy, as well as to a decrease of the Hall mobility of carriers along layers. The theoretical analysis of the mobility of carriers has shown that space-charge regions underlie the effective mechanism of their scattering. 2008 Article Electrical properties of fast cooled InSe single crystals / A.V. Zaslonkin, Z.D. Kovalyuk, I.V. Mintyanskii, P.I. Savitskii // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2008. — Т. 11, № 1. — С. 54-58. — Бібліогр.: 17 назв. — англ. 1560-8034 PACS 72.20.Dp, 72.20.-i, 81.10.Fq http://dspace.nbuv.gov.ua/handle/123456789/118664 en Semiconductor Physics Quantum Electronics & Optoelectronics Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| language |
English |
| description |
Influence of fast cooling on electrical properties of n-InSe single crystals is
investigated for an ingot grown by the Bridgman method. Electrical characteristics and
their anisotropy are investigated in the temperature range 80 to 410 K. It is found that
fast cooling, as soon as crystallization is completed, of the ingot leads to an increase of
the free electron concentration, conductivity along layers, and conductivity anisotropy, as
well as to a decrease of the Hall mobility of carriers along layers. The theoretical analysis
of the mobility of carriers has shown that space-charge regions underlie the effective
mechanism of their scattering. |
| format |
Article |
| author |
Zaslonkin, A.V. Kovalyuk, Z.D. Mintyanskii, I.V. Savitskii, P.I. |
| spellingShingle |
Zaslonkin, A.V. Kovalyuk, Z.D. Mintyanskii, I.V. Savitskii, P.I. Electrical properties of fast cooled InSe single crystals Semiconductor Physics Quantum Electronics & Optoelectronics |
| author_facet |
Zaslonkin, A.V. Kovalyuk, Z.D. Mintyanskii, I.V. Savitskii, P.I. |
| author_sort |
Zaslonkin, A.V. |
| title |
Electrical properties of fast cooled InSe single crystals |
| title_short |
Electrical properties of fast cooled InSe single crystals |
| title_full |
Electrical properties of fast cooled InSe single crystals |
| title_fullStr |
Electrical properties of fast cooled InSe single crystals |
| title_full_unstemmed |
Electrical properties of fast cooled InSe single crystals |
| title_sort |
electrical properties of fast cooled inse single crystals |
| publisher |
Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України |
| publishDate |
2008 |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/118664 |
| citation_txt |
Electrical properties of fast cooled InSe single crystals / A.V. Zaslonkin, Z.D. Kovalyuk, I.V. Mintyanskii, P.I. Savitskii // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2008. — Т. 11, № 1. — С. 54-58. — Бібліогр.: 17 назв. — англ. |
| series |
Semiconductor Physics Quantum Electronics & Optoelectronics |
| work_keys_str_mv |
AT zaslonkinav electricalpropertiesoffastcooledinsesinglecrystals AT kovalyukzd electricalpropertiesoffastcooledinsesinglecrystals AT mintyanskiiiv electricalpropertiesoffastcooledinsesinglecrystals AT savitskiipi electricalpropertiesoffastcooledinsesinglecrystals |
| first_indexed |
2025-07-08T14:24:51Z |
| last_indexed |
2025-07-08T14:24:51Z |
| _version_ |
1837089100641861632 |
| fulltext |
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2008. V. 11, N 1. P. 54-58.
© 2007, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
54
PACS 72.20.Dp, 72.20.-i, 81.10.Fq
Electrical properties of fast cooled InSe single crystals
A.V. Zaslonkin, Z.D. Kovalyuk, I.V. Mintyanskii, and P.I. Savitskii
I.M. Frantsevich Institute of Materials Science Problems,
National Academy of Sciences of Ukraine, Chernivtsi Department
5, Iryna Vilde str., 58001 Chernivtsi, Ukraine; e-mail: chimsp@ukrpost.ua
Abstract. Influence of fast cooling on electrical properties of n-InSe single crystals is
investigated for an ingot grown by the Bridgman method. Electrical characteristics and
their anisotropy are investigated in the temperature range 80 to 410 K. It is found that
fast cooling, as soon as crystallization is completed, of the ingot leads to an increase of
the free electron concentration, conductivity along layers, and conductivity anisotropy, as
well as to a decrease of the Hall mobility of carriers along layers. The theoretical analysis
of the mobility of carriers has shown that space-charge regions underlie the effective
mechanism of their scattering.
Keywords: indium selenide, layered crystal, conductivity anisotropy, scattering
mechanism.
Manuscript received 02.02.07; accepted for publication 07.02.08; published online 31.03.08.
1. Introduction
A crucial distinction between the chemical bonds along
and across the layers in indium selenide determines the
anisotropy of its physical properties and the peculiarities
of applications in semiconductor electronics. Having the
energy gap Eg ∼ 1.24 eV and the free electron concent-
ration ∼1015 cm–3 at the electron mobility ∼103 cm2/(V·s)
at room temperature, the material is perspective for
different semiconductor devices. In particular, InSe is a
good candidate for photovoltaic conversion of the solar
energy [1] as the inactivity of cleaved InSe surfaces to
the adsorption of foreign impurities makes it possible to
prepare efficient photosensitive barrier structures highly
resistant to hard radiation by means of comparatively
simple technologies [2]. The natural photopleochroism
gives a possibility for creation of InSe-based polarized
light analyzers [3]. An obvious potential of InSe is also
related to its application as an intercalation cathode
material in solid-state batteries [4], a host material for
accumulation of hydrogen [5], and realization of its
nano-structured forms.
However, the efficiency of the device structures is
restricted to defects being appeared at the growing of
single crystals. At the same time, it is known that, due to
the peculiarities of the In – Se phase diagram [6] and the
highest bond ionicity in indium monoselenide in
comparison to other layered III-VI compounds [7], it is
most difficult to obtain structurally perfect single
crystals just of InSe. As electrical parameters and their
dependence on different technological factors are
concerned, they are at the first place in the fabrication of
conventional semiconductor compounds. But the
situation with InSe is exceptional to a considerable
degree, and the disagreement between the literature data
is high in comparison with other layered III-VI crystals.
In particular, extremely different values of the
conductivity components in the different crystallo-
graphic directions σ⊥C and σ⎪⎪C (conductivities along and
across the layers, respectively) have been observed in
spite of the fact that the corresponding effective masses
are related as m*⊥C > m*⎪⎪C. This complicates the
realization of potential advantages of InSe. For example,
in InSe-based barrier structures, the series resistance
increases, and the diffusion length of photocarriers
become lower.
Therefore, technological experiments and inves-
tigations of different defects in InSe aimed at the
fabrication of high-quality single crystals with stable and
reproducible parameters keep their urgency. From the
previous studies, it is known [8-10] that vacuum
annealing of InSe single crystals affects their transport
properties in different ways depending on the
temperature, duration, and cooling conditions. In this
paper, we first investigate the influence of fast cooling of
an InSe ingot to room temperature as soon as the
crystallization is completed. The electrical characte-
ristics of the ingot are obtained, their anisotropy is
measured, and the results are analyzed taking different
scattering mechanisms into account.
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2008. V. 11, N 1. P. 54-58.
© 2007, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
55
2. Experimental
For investigations, an InSe single crystal was grown by
the Bridgman method from a non-stoichiometric melt
In1.05Se0.95. As usual, after a single crystal stops to
grow, its cooling to room temperature takes place under
conditions of a “switched-off” furnace (slow cooling)
during 10 to 12 h. In our case, the cooling of the ingot
of as-grown layered InSe has been carried out by
means of the quick taking out of the ampoule from a
heated furnace after the growth is completed. As a
result, the cooling time was reduced to several tens of
minutes. Since the ingot still remains in the field of a
furnace temperature gradient after the growth
termination, the samples for investigations were cut
from its parts which had different temperatures before
cooling: 450±5, 505±5, and 555±5 °C (samples 1 to 3,
respectively).
The measurements of the Hall effect and conduc-
tivity along layers σ⊥C were performed with samples of
rectangular form with typical dimensions of about
10×2×0.6 mm. Indium contacts to them were soldered in
the classical configuration. The electron concentration n
was determined from the Hall coefficient RH using the
relation n = r / eRH with the Hall factor r = 1. The mea-
surements of the conductivity across layers σ⎪⎪C were
carried out on samples with typical dimension of the
cleaved plane of about 4×5 mm and about 0.6 to 0.8 mm
in thickness. Current contacts covered almost the whole
cleaved surfaces, and the voltage was measured between
a pair of small-area contacts close to them. Temperature
dependences were measured in the range 80 to 400 K.
3. Results and discussion
The temperature dependences of the free electron
concentration n are shown in Fig. 1 for fast cooled
samples 1 to 3. The typical dependence for a slowly
cooled InSe sample (curve 4) is also presented for
comparison. The change of the electron concentration
with temperature in the range T < 300 K is slight and
practically the same for all the investigated crystals. But,
in comparison with the slowly cooled crystals, the
influence of fast cooling results in essentially higher
values of n over all the temperature range. This indicates
the presence of a shallow donor level in the energy gap
of InSe which is already predominantly ionized at 77 K.
It is generally accepted for this level to be related to
interstitial In atoms [8, 9, 11, 12]. The activation energy
of this level, established from electrical measurements
[8, 9], is equal to 0.012–0.015 eV. At temperatures
T > 300 K, the free electron concentration increases due
to the ionization of a deeper donor level. Its activation
energy ∆E, determined from the slope in the lg(nT-3/4) =
ϕ(103/T) dependence, is 0.38–0.40 eV. The presence of
this level is not typical of slowly cooled InSe ingots with
the same order of the free electron concentration.
3 6 9 12
1015
1016
n,
c
m
-3
1000/T, K-1
3
2
1
4
Fig. 1. Temperature dependences of the electron concentration
for samples from the fast (1 to 3) and slowly (4) cooled InSe
ingots. Curves 1 to 3 corresponds to the samples from the ingot
parts with different temperatures before cooling: 450±5,
505±5, and 555±5 °C, respectively.
For all the investigated samples in the temperature
range T < 300 K, the conductivity along the layers
(Fig. 2) has “metallic” behavior. It takes place because
the electron concentration increases more slightly with
temperature in comparison with a decrease of the Hall
mobility along the layers. Above room temperature, the
conductivity has typical semiconductor character due to
an abrupt increase of n. For the fast cooled samples, the
σ⊥C values are essentially higher.
3 6 9 12
1
3
2
1
4
3
0.5
C
, O
hm
-1
⋅c
m
-1
σ
⊥
1000/T, K-1
Fig. 2. Temperature dependences of the conductivity along the
layers for samples from the fast (1 to 3) and slowly (4) cooled
InSe ingots. The notation of curves 1-3 is the same as in Fig. 1.
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2008. V. 11, N 1. P. 54-58.
© 2007, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
56
100 200 300 400
103
104
C
, c
m
2 /V
⋅s
4
1
2
3
µ ⊥
Temperature, K
Fig. 3. Temperature dependences of the Hall mobility along
the layers for samples from the fast (1 to 3) and slowly (4)
cooled InSe ingots. The notation of curves 1 to 3 is the same as
in Fig. 1. Symbols – the experimental data, lines – the calcu-
lated dependences: 1 to 3 – µph+BH+SC, 4 – µph+BH.
Figure 3 shows the temperature dependence of the
Hall electron mobility µ⊥С along the layers for fast
cooled samples 1 to 3 (curves 1-3). In comparison with
the slowly cooled sample (curve 4), the influence of this
technological procedure leads to its decrease and the
appearance of some peculiarities in the high-temperature
range. Like to the slowly cooled sample, there is no
tendency to create a maximum in the µ⊥С(Т) depen-
dences. That is, a transition to the predominant scattering
of carriers by ionized impurities does not occur even at
T = 80 K. In order to analyze the observed µ⊥С(Т)
dependences, the contributions of various scattering
mechanisms to the total mobility µ supposed to be
expressed by the Matthiessen rule
∑ −− µ=µ
i
i
11
were determined as a result of numerical calculations for
separate mechanisms µi. The temperature dependence of
the mobility due to the lattice scattering has been
analyzed on the basis of a three-dimensional model for
the short-range interaction of electrons with homopolar
optical phonons polarized along the crystallographic C
axis [13, 14]. In this case, the drift mobility has the form
( ) ( ) ,exp
3
4 2/3
0
*ph dUUUU
m
e
−τ
π
=µ ∫
∞
(1)
where ,/ kTU ε= ε is the energy of carriers, k is the
Boltzmann constant, τ is the relaxation time, and
( ) 31
||
2
CC mmm ⋅= ⊥
∗ is the average electron effective
mass equal to 0.112 m0 [11] for InSe. Like the majority
of papers concerning the transport properties of InSe,
our calculations were carried out for the low-energy
phonon mode '
1gA (ħω = 14.3 meV) which only deforms
the In-In bonding at the electron-phonon coupling
constant g2 = 0.051.
Assuming the Brooks-Herring equation [15] to be
true for the scattering by ionized impurities, the total
mobility due to both mechanisms is given as
1
BH
1
ph
1 −−− µ+µ=µ . This expression well reproduces the
µ⊥С(Т) dependence for the slowly cooled sample
(curve 4 in Fig. 3), but it is not sufficient for the fast
cooled samples. Let us analyze this situation by using
sample 3 as an example (Fig. 4). If one determines the
ion concentration Ni from the coincidence between the
experimental µ⊥С and calculated µ mobilities at 80 K,
where the interaction with ions is most essential, the
calculated curve goes over the experimental one at
higher temperatures (curve 3 in Fig. 4). When the fitting
is done at T = 293 K, the calculated µ (Т) values are too
low at the liquid nitrogen temperature (curve 1).
This circumstance along with the observed µ⊥С(Т)
peculiarities at T > 300 K for the fast cooled samples
lead to the necessity to take the additional scattering
mechanism into account which should be stronger at
high temperatures. As such a mechanism for n-InSe, the
electron scattering by space-charge regions (SCRs) was
considered in [16]. When the SCR radius RSC is less than
the carrier mean free-path, the regions act as scatterers.
Assuming that free carriers cannot penetrate into such
regions with effective cross-section Q and suggesting
that it is related to the Debye screening length Dr as Q ∼
2
Dr , we get the Weisberg expression for the corres-
ponding mobility µSC [17] in the form
( )
2/3
SC
2/1
2/33
SC
1
2
4 −
∗κ
=µ nT
Nm
ke
. (2)
100 200 300 400
103
104
105
5
4
3
2
1
M
ob
ilit
y,
ñ
m
2 /V
⋅s
Ê
6
Temperature, K
Fig. 4. Partial contributions of the different scattering mecha-
nisms to the total mobility for sample 3 in Fig. 3. Symbols –
the experimental data, lines – the calculated dependences:
1 and 3 – µph+BH, 2 – µph+BH+SC, 4 – µSC, 5 – µph, and 6 – µBH.
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2008. V. 11, N 1. P. 54-58.
© 2007, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
57
3 6 9 1 2
1 0 -4
1 0 -3
1 0 -2
1 0 -1
1 0 0
1 0 1
C
, O
hm
-1
⋅c
m
-1
4
3
2
1
σ ⎢
⎢
1 0 0 0 /T , K -1
Fig. 5. Temperature dependences of the conductivity across
the layers for samples from the fast (1 to 3) and slowly (4)
cooled InSe ingots. The notation of curves 1 to 3 is the same
as in Fig. 1.
Table. Parameters of the n-InSe samples presented in Fig. 3.
Sample
80 K
n (cm-3) µ⊥C
(cm2/V⋅s)
Q (cm2) NSC (cm-3) Ni (cm-3)
1 2.51×1015 7900 1.08×10-10 1.70×1014 7.37×1015
2 4.15×1015 5510 6.52×10-9 3.22×1015 6.52×1015
3 7.50×1015 3920 3.99×10-9 9.93×1015 9.91×1015
4 1.15×1015 12180 – – 3.70×1015
Here, κ is the InSe permittivity, and NSC is the
concentration of space-charge regions. The three above-
mentioned scattering mechanisms give the total mobility
1
SC
1
BH
1
ph
1 −−−− µ+µ+µ=µ . (3)
From the fitting of the calculated curve based on
Eq. (3) to the experimental data, we have obtained some
parameters of scattering centers. They are listed in
Table. For sample 3, the contribution of the different
scattering mechanisms to the total mobility is shown in
Fig. 4. As one can see from the obtained results, the
peculiarities of the measured µ⊥С(Т) dependences above
300 K for the fast cooled samples are due to the
interaction of electrons with SCRs. The abrupt increase
of the free electron concentration due to the activation
from the deep donor level leads to the increase of µSC
with temperature, i.e. SCRs scatter less essentially
because of their screening with electrons (curve 4 in
Fig. 4).
The conductivity across the layers for InSe samples
prepared from the same ingot parts is shown in Fig. 5. It
makes possible to estimate the conductivity anisotropy.
It is known [8, 10] that, in n-InSe, the ratio σ⊥C / σ⎪⎪C
varies from several units up to 105. But the high aniso-
tropy ratio cannot be supposed to be a result of a two-
dimensional band structure, as the numerical cal-
culations and many experimental data indicate the three-
dimensional character of the bands forming the
fundamental absorption edge. The wide variation of the
anisotropy is due to the presence of uncontrolled
impurities including aggregates of over-stoichiometric In
or dopants at the interlayer stacking faults. Such a
disordering restricts the electron transport along the C
axis. Therefore, the obtained high values of σ⊥C / σ⎪⎪C
(∼103) for fast cooled samples 1 and 2 in Fig. 5 indicate
the high amount of defect interlayer spaces. As for
sample 3 from the upper part of the ingot, the suddenly
low anisotropy ratio (σ⊥C / σ⎪⎪C is even below unity at
300 K) takes place most likely due to possible indium
shorting jumpers between the layers what, in turn, results
in the increase of σ⎪⎪C.
4. Conclusions
Electrical characteristics of InSe single crystals grown
by the Bridgman method essentially depend on cooling
conditions of the ingots after ending the crystal growth.
In comparison with the conventional cooling under
conditions of a “switched-off” furnace, the fast cooling
leads to an essential increase of the free electron
concentration and a decrease of the Hall mobility along
the layers and its peculiarities in the high-temperature
range. For the samples from the fast cooled ingot, the
interaction of electrons with space-charge regions
becomes the effective scattering mechanism. The higher
the temperature of the ingot parts before cooling, the
higher the concentration of these regions.
Acknowledgement
This work was supported by the Science and Technology
Center of Ukraine (grant No. 3237).
References
1. A. Segura, J.P. Guesdon, J.M. Besson, A. Chevy,
Photoconductivity and photovoltaic effect in
indium selenide // J. Appl. Phys. 54(2), p. 876-888
(1983).
2. Z.D. Kovalyuk, V.M. Katerynchuk, I.V. Min-
tyanskii, A.I. Savchuk, O.M. Sydor, γ-Radiation
influence on the photoelectrical properties of oxide
– p-InSe heterostructure // Mater. Sci. Eng. B 118
(1), p. 147-149 (2005).
3. Z.D. Kovalyuk, V.M. Katerynchuk, T.V. Betsa,
Photoresponse spectral investigations for aniso-
tropic semiconductor InSe // Optical materials, 17
(2), p. 279-281 (2001).
4. M. Balkanski, Solid-state microbatteries for elect-
ronics in the 21st century // Solar Energy Materials
and Solar Cells 62(1-2), p. 21-35 (2000).
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2008. V. 11, N 1. P. 54-58.
© 2007, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
58
5. Yu.I. Zhirko, I.P. Zharkov, Z.D. Kovalyuk,
M.M. Pyrlja, V.B. Boledzyuk, On Wannier exciton
2D localization in hydrogen intercalated InSe and
GaSe layered semiconductor crystals // Semicon-
ductor Physics, Quantum Electronics & Opto-
electronics 7(4), p. 404-410 (2004).
6. K. Imai, K. Susuki, T. Haga, Y. Hasegava, Y. Abe,
Phase diagram of In – Se system and crystal growth
of indium monoselenide // J. Cryst. Growth 54 (3),
p. 501-506 (1981).
7. Y. Nishina, K. Kuroda, Lattice instability of IIIB –
VIB layer compounds // Physica B+C 99(1-4),
p. 357-360 (1980).
8. P.I. Savitskii, I.V. Mintyanskii, Z.D. Kovalyuk,
Annealing effect on conductivity anisotropy in
indium selenide single crystals // Phys. status solidi
(a) 155 (2), p. 451-460 (1996).
9. P.I. Savitskii, Z.D. Kovalyuk, I.V. Mintyanskii,
Thermally stimulated changes in the defect struc-
ture of indium monoselenide // Neorganich.
Materialy 33(9), p. 897-901 (1997) (in Russian).
10. P.I. Savitskii, Z.D. Kovalyuk, I.V. Mintyanskii,
Anisotropy of electrical conductivity in indium se-
lenide // Ibid. 32(4), p.361-365 (1996) (in Russian).
11. A. Segura, F. Pomer, A. Cantarero, W. Krause,
A. Chevy, Electron scattering mechanism in n-type
indium selenide // Phys. Rev. B 29(10), p. 5708-
5717 (1984).
12. A. Segura, K. Wünstel, A. Chevy, Investigation of
impurity levels in n-type indium selenide by means
of Hall effect and deep level transient spectroscopy
// Appl. Phys. A 31 (2), p. 139-145 (1983).
13. R.C. Fivaz, Ph. Schmid, Transport properties of
layered semiconductors, In: Optical and Electrical
Properties / Ed. P.A. Lee. D. Reidel Publ. Co.,
Dordrecht, 1976, p. 343-384.
14. Ph. Schmid, Electron-lattice interaction in layered
semiconductors // Nuovo Cim. B 21(2), p. 258-272
(1974).
15. K. Seeger, Semiconductor Physics. Springer,
Vienna, 1973.
16. P.I. Savitskii, Z.D. Kovalyuk, I.V. Mintyanskii,
Space-charge region scattering in indium mono-
selenide // Phys. status solidi (a), 180(2), p. 523-
531 (2000).
17. L.R. Weisberg, Anomalous mobility effects in
some semiconductors and insulators // J. Appl.
Phys. 33(5), p. 1817-1821 (1962).
|