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1.
The results of calculations of the band gap in GaP
x
N
y
As1 − x − y
alloys and the estimated parameter of hybridization of the conduction band in GaP and the localized level of nitrogen are
reported. The optical properties of quantum-confined heterostructures based on GaP
x
N
y
As1 − x − y
alloys synthesized on the GaP (100) substrate surface are studied by photoluminescence measurements in the temperature range
of 15–300 K. The heterostructures consist of GaP0.814N0.006As0.18 quantum wells separated by GaP barrier layers. The well width and the barrier thickness are 5 nm. Heterostructures with different
numbers of periods are considered. On optical excitation of the structures, an intense photoluminescence line is observed
in the spectral range 620–650 nm. The photoluminescence spectra of the GaP0.814N0.006As0.18/GaP quantum wells are profoundly broadened because of the inhomogeneity of the quaternary alloy in composition. It is established
that the increase in the number of quantum well layers from 10 to 25 does not results in degradation of the photoluminescence
properties of the heterostructures. The results of the study support the view that it is possible to produce efficient optoelectronic
devices on the basis of GaP
x
N
y
As1 − x − y
alloys. 相似文献
2.
The optical properties of quaternary GaN
x
As
y
P1 − x − y
semiconductor alloys grown on a GaP (100) substrate surface are studied by photoluminescence spectroscopy in the temperature
range 20–300 K and by photoluminescence excitation spectroscopy at liquid-nitrogen temperature. The measurements are carried
out for the GaN
x
As
y
P1 − x − y
alloys, for which the nitrogen and arsenic molar fractions x and y range from 0.006 to 0.012 and from 0.00 to 0.18, respectively. A comparative analysis of the data is conducted, and the dependences
of the energy position of the photoluminescence peak on the composition of the quaternary alloy are established. From the
studies of photoluminescence in the range 20–300 K, it is found that the temperature dependence of the position of the photoluminescence
peak substantially differs from the behavior described by Varshni’s expression. 相似文献
3.
T. Ohnishi M. Naito S. Mizusaki Y. Nagata Y. Noro 《Journal of Electronic Materials》2011,40(5):915-919
The magnetic, transport, and thermoelectric properties of Ca1−x
Sr
x
Ru1−y
Mn
y
O3 have been investigated. Ferromagnetism with relatively high T
C (>200 K) was introduced by Mn doping. In particular, ferromagnetism appeared in the Ca0.5Sr0.5Ru1−y
Mn
y
O3 system at y > 0.2. The maximum T
C (=270 K) was recorded for a specimen of Ca0.5Sr0.5Ru0.4Mn0.6O3. The ferromagnetism seems to be due to the mixed-valence states of Mn3+, Mn4+, Ru4+, and Ru5+ ions. The metallic character of Ru-rich specimens was suppressed by Mn substitution, and the system was transformed into
a semiconductor at relatively low Mn content near y = 0.1. Specimens with higher Mn content (y > 0.8) had large thermoelectric power (50 μV K−1 to 130 μV K−1 at 280 K) accompanied by relatively low resistivity (0.03 Ω cm to 1 Ω cm). The Ca0.5Sr0.5Ru1−y
Mn
y
O3 system seems to have good potential as a thermoelectric material for use above 300 K. 相似文献
4.
P. V. Seredin A. V. Glotov V. E. Ternovaya E. P. Domashevskaya I. N. Arsentyev L. S. Vavilova I. S. Tarasov 《Semiconductors》2011,45(11):1433-1440
Using X-ray structural analysis, scanning electron microscopy, atomic force microscopy, and photoluminescent spectroscopy,
it is shown that it is possible to obtain a small-scale domain structure on the surface of liquid-phase epitaxial heterostructures.
The domain structure emerges as a result of spinodal decomposition of the Ga
x
In1 − x
As
y
P1 − y
quaternary alloy due to immiscibility of its components and relaxation of its lattice parameter to surrounding layers. 相似文献
5.
E. P. Domashevskaya N. N. Gordienko N. A. Rumyantseva B. L. Agapov P. V. Seredin L. A. Bityutskaya I. N. Arsentev L. S. Vavilova I. S. Tarasov 《Semiconductors》2008,42(9):1069-1075
Structural and optical properties of two- and three-layer epitaxial heterostructures containing GaInP/Ga
x
In1 − x
As
y
P1 − y
quaternary alloy layers were studied. Domain formation due to spinodal decomposition of the quaternary alloy was detected
in three-layer heterostructures. As a result, an additional long-wavelength band appears in the photoluminescence spectra,
and an additional doublet of the line appears in X-ray diffraction patterns of the (006) line. The domain composition was determined on the basis of Vegard’s
law and the Kouphal equation.
Original Russian Text ? E.P. Domashevskaya, N.N. Gordienko, N.A. Rumyantseva, B.L. Agapov, P.V. Seredin, L.A. Bityutskaya,
I.N. Arsent’ev, L.S. Vavilova, I.S. Tarasov, 2008, published in Fizika i Tekhnika Poluprovodnikov, 2008, Vol. 42, No. 9, pp.
1086–1093. 相似文献
6.
Masayuki Hasaka Takao Morimura Hanae Sato Hiromichi Nakashima 《Journal of Electronic Materials》2009,38(7):1320-1325
Ribbons of Ti
x
(Hf
y
Zr1−y
)1−x
NiSn1−z
Sb
z
(x = 0.1 to 1, y = 0.1 to 0.9, z = 0, 0.002, 0.004) were prepared by spin casting and annealed for 1 h at T
a = 1000 K, 1050 K, 1073 K, and 1100 K. The crystal phase of the ribbons was investigated by x-ray diffraction analysis and
transmission electron microscopy. All the ribbons consisted of a phase with a half-Heusler structure. The Seebeck coefficient,
electrical conductivity, thermal conductivity, power factor, and figure of merit ZT at room temperature were clarified experimentally as a function of x, y, z, and T
a. Despite the large thermal conductivity, the power factor and figure of merit were remarkably large at x = 0.5, y = 0.5, z = 0.002, and T
a = 1073 K, because the Seebeck coefficient and electrical conductivity were large. 相似文献
7.
The influence of hydrogenation on the electrical properties of the CdxHg1 ? xTe epitaxial structures
V. S. Varavin G. Yu. Sidorov M. O. Garifullin A. V. Vishnyakov Yu. G. Sidorov 《Semiconductors》2011,45(3):397-402
The phenomenon of hydrogenation of the Cd
x
Hg1 − x
Te films is studied. Hydrogenation was performed via either boiling the Cd
x
Hg1 − x
Te films in deionized water or using the electrochemical treatment. It is established that, during contacts with aqueous media,
the acceptor centers are introduced into the films; their concentration can exceed 1017 cm−3. It is shown that two types of hydrogen-based acceptors are introduced, namely, fast and slow acceptors, and their diffusivities
are evaluated. It is found that hydrogen partially exists after treatment in an electrically inactive form and can be activated
with further storage or during heating. After activation, the hole concentration can become as high as 1018 cm−3. The influence of pH of the medium on the rate of introduction of hydrogen into the material is discussed. 相似文献
8.
The influence of temperature and Ga composition on Auger recombination lifetime in n-type and p-type In1-xGaxAs materials is investigated through the simulation, assuming the concentrations of electrons and holes are 1017 cm-3 and 1018 cm-3, respectively. The results show that the temperature has little influence on Auger recombination lifetime of In1-xGaxAs materials at x<0.3. However, it has a great impact when x>0.3 and the effect is more obvious at a lower temperature. Moreover, Auger ... 相似文献
9.
The field dependence of drift velocity of electrons in quantum wells of selectively doped In0.5Ga0.5As/Al
x
In1 − x
As and In0.2Ga0.8As/Al
x
Ga1 − x
As heterostructures is calculated by the Monte Carlo method. The influence of varying the molar fraction of Al in the composition
of the Al
x
Ga1 − x
As and Al
x
In1 − x
As barriers of the quantum well on the mobility and drift velocity of electrons in high electric fields is studied. It is
shown that the electron mobility rises as the fraction x of Al in the barrier composition is decreased. The maximum mobility in the In0.5Ga0.5As/In0.8Al0.2As quantum wells exceeds the mobility in a bulk material by a factor of 3. An increase in fraction x of Al in the barrier leads to an increase in the threshold field E
th of intervalley transfer (the Gunn effect). The threshold field is E
th = 16 kV/cm in the In0.5Ga0.5As/Al0.5In0.5As heterostructures and E
th = 10 kV/cm in the In0.2Ga0.8As/Al0.3Ga0.7As heterostructures. In the heterostructures with the lowest electron mobility, E
th = 2–3 kV/cm, which is lower than E
th = 4 kV/cm in bulk InGaAs. 相似文献
10.
Complete mutual solubility in the (In2S3)
x
(FeIn2S4)1 − x
system is established. The technology is developed, and single crystals of the continuous series of the (In2S3)
x
(FeIn2S4)1 − x
solid solutions are grown for the first time. The linear dependence of the unit cell parameter of single crystals with a
cubic spinel lattice on the solid solution composition is found. First, photosensitive Schottky barriers are fabricated, and
then, based on studies of their photosensitivity, the character of band-to-band transition is discussed and the values of
the band gap depending on the atomic composition are estimated. The possibility of using the obtained solid solutions as broadband
photoconverters of optical radiation is revealed. 相似文献
11.
S. H. Yang T. J. Zhu C. Yu J. J. Shen Z. Z. Yin X. B. Zhao 《Journal of Electronic Materials》2011,40(5):1244-1248
(GeTe)90(Ag
y
Sb2−y
Te3−y
)10 (y = 0.6, 0.7, 0.8, 1.0) compounds were prepared by combining melting and hot pressing, and the thermoelectric properties were
studied over the temperature range of 300 K to 770 K. Powder x-ray diffraction results revealed that all the samples were
the rhombohedral phase with space group R3m. The electrical conductivity of samples decreased with temperature, while the Seebeck coefficient increased. The thermal
conductivity of all the samples was very low, especially for those with the lower y values. High ZT values above 1.6 were obtained for the samples with y = 0.6, 0.7, and 0.8. 相似文献
12.
Enrico Furno Simone Chiaria Michele Penna Enrico Bellotti Michele Goano 《Journal of Electronic Materials》2010,39(7):936-944
As a preparatory step toward establishing reliable numerical design tools for ZnO-based optoelectronic devices, we have reassessed
the available information on material parameters relevant for the simulation of light-emitting diodes (LEDs) with active regions
including ZnO, MgZnO, and BeZnO layers. The impact of different approximations for the electronic structure and the interface
polarization charge on the optical properties of bulk ZnO and ZnO/MgZnO quantum wells has been evaluated, and a consistent
set of parameters has been used not only for systematic comparison of ZnO/MgZnO and ZnO/BeZnO single quantum well structures
but also for the first simulation of a realistic ZnO/BeZnO multiple quantum well LED. 相似文献
13.
The experimental results of synthesizing thin films (<1 μm thick) of (SnO2)
x
(In2O3)1 − x
(x = 0.5–1 wt) nanocomposites fabricated by high-frequency magnetron sputtering of metal-oxide targets in a controlled Ar +
O2 atmosphere are presented. The films, deposited on hot substrates (400°C), are studied by the X-ray diffraction analysis,
atomic-force microscopy, and optical and electrical methods. The effect of the synthesis conditions and film composition on
the size of crystalline grains, band gap, and the concentration and mobility of free charge carriers was determined. It is
shown that films of the composition (SnO2)
x
(In2O3)1 − x
with x = 0.9 are the most promising for applications in gas sensorics. 相似文献
14.
G. F. Kuznetsov 《Semiconductors》2009,43(4):472-479
By the specified program of computer control over the growth process, superlattices of the In
x
Ga1 − x
As/GaAs/.../GaAs(001) type with the number of alternating pairs N
1 = 12, N
2 = 6, and N
3 = 3 were grown. Using the X-ray methods of quantitative analysis, the values of periods T
1 = 22 nm, T
2 = 22.5 nm, and T
3 = 22.3 nm and the In content x
1 = 0.09, x
2 = 0.091, and x
3 = 0.092 in these superlattices are measured. In the superlattice with N
1 = 12, the plastic deformation is detected. In superlattices with N
2 = 6 and N
3 = 3, no plastic deformation during the growth was observed. The obtained magnitudes of the periods turned out smaller by
a factor of approximately 2 and the alloy concentration turned out smaller by 1/3 than it was specified by the computer program.
The measured and calculated values of elastic stresses turned out equal to σ2N
= 2.43 × 106 Pa and σ2N − 1 = −0.88 × 109 Pa, at which the plastic deformation took place in the layers of the superlattice with N
1 = 12. In superlattices with N
2 = 6 and N
3 = 3, the elastic stresses were σ2N
= 1.96 × 10 6 Pa, σ2N − 1 = −1.45 × 109 Pa and σ2N
= 0.99 × 106 Pa, σ2N − 1 = −1.88 × 109 Pa, respectively. These stresses turned out insufficient to initiate the process of dislocation generation.
Original Russian Text ? G.F. Kuznetsov, 2009, published in Fizika i Tekhnika Poluprovodnikov, 2009, Vol. 43, No. 4, pp. 493–500. 相似文献
15.
J. Leszczynski A. Dauscher P. Masschelein B. Lenoir 《Journal of Electronic Materials》2010,39(9):1764-1768
Interesting results for cobalt triantimonide partially filled with indium have encouraged us to explore skutterudites filled
with higher indium fractions. For pure In
x
Co4Sb12, the fraction of voids filled is limited to about x = 0.25. To enable the insertion of more indium atoms, charge compensation is necessary. In this work, we studied the skutterudite
compound In
x
Fe
y
Co4−y
Sb12 partially filled with indium, where iron substitution for cobalt was employed for charge compensation. Polycrystalline samples
were prepared by direct reaction of constituents. Structural and chemical characterization were accomplished by x-ray diffraction
and energy-dispersive x-ray spectroscopy. Electrical resistivity, thermoelectric power, and thermal conductivity were measured
between 2 K and 350 K. The influence of indium and iron on the charge-carrier transport properties and thermal conductivity
in In
x
Fe
y
Co4−y
Sb12 compounds is presented and discussed. 相似文献
16.
A technology of growing single crystals of (In2S3)
x
(MnIn2S4)1 − x
solid solutions that provides control over their atomic composition in the entire concentration range 0 ≤ x ≤ 1 is developed. It is shown that, in the range x = 0–1, the single crystals have the cubic spinel structure and the unit cell parameter a follows the linear dependence on x. The exponential character of the temperature dependence of resistivity of solid solutions, on which the first photosensitive
Cu/(In2S3)x(MnIn2S4)1 − x
structures are obtained, is revealed. The first photosensitivity spectra of these structures are obtained, and, based on
these spectra, dependences of energy of the direct and indirect band-to-band transitions on the composition x are determined. The possibility of applying these structures in broad-band photoconverters of optical radiation is concluded. 相似文献
17.
Fuad Al-Amoody Ernesto Suarez Angel Rodriguez E. Heller Wenli Huang F. Jain 《Journal of Electronic Materials》2011,40(8):1699-1705
This paper presents a floating quantum dot (QD) gate nonvolatile memory device using high-energy-gap Zn
y
Cd1−y
Se-cladded Zn
x
Cd1−x
Se quantum dots (y > x) with tunneling layers comprising nearly lattice-matched semiconductors (e.g., ZnS/ZnMgS) on Si channels. Also presented
is the fabrication of an electroluminescent (EL) device with embedded cladded ZnCdSe quantum dots. These ZnCdSe quantum dots
were embedded between indium tin oxide (ITO) on glass and a top Schottky metal electrode deposited on a thin CsF barrier.
These QDs, which were nucleated in a photo-assisted microwave plasma (PMP) metalorganic chemical vapor deposition (MOCVD)
reactor, were grown between the source and drain regions on a p-type silicon substrate of the nonvolatile memory device. The composition of QD cladding, which relates to the value of y in Zn
y
Cd1−y
Se, was engineered by the intensity of ultraviolet light, which controlled the incorporation of zinc in ZnCdSe. The QD quality
is comparable to those deposited by other methods. Characteristics and modeling of the II–VI quantum dots as well as two diverse
types of devices are presented in this paper. 相似文献
18.
Design of GaAs/AlxGa1?xAs asymmetric quantum wells for THz-wave by difference frequency generation
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The energy levels, wave functions and the second-order nonlinear susceptibilities are calculated in GaAs/Al0.2Ga0.8As/Al0.5Ga0.5As asymmetric quantum well (AQW) by using an asymmetric model based on the parabolic and non-parabolic band. The influence of non-parabolicity can not be neglected when analyzing the phenomena in narrow quantum wells and in higher lying subband edges in wider wells. The numerical results show that under double resonance (DR) conditions, the second-order difference frequency generation (DFG) and optical rectification (OR) generation susceptibilities in the AQW reach 2.5019 mm/V and 13.208 mm/V, respectively, which are much larger than those of the bulk GaAs. Besides, we calculate the absorption coefficient of AQW and find out the two pump wavelengths correspond to the maximum absorption, so appropriate pump beams must be selected to generate terahertz (THz) radiation by DFG. 相似文献
19.
D. A. Pashkeev Yu. G. Selivanov E. G. Chizhevskii D. B. Stavrovskii I. I. Zasavitskiy 《Semiconductors》2011,45(8):980-987
The transmittance spectra of epitaxial Pb1 − x
Eu
x
Te (0 ≤x ≤ 0.1) alloy layers are exploited to study the dispersion of their refractive index in the spectral range from 650 to 8000
cm−1 (below the absorption edge). The refractive index and the position of the absorption edge as functions of the composition
parameter of the alloys are determined at two temperatures, 80 and 295 K. The refractive index is calculated in the context
of the classic wave concepts of propagation of electromagnetic radiation. The experimentally determined dispersion dependences
are described by the empiric Sellmeier expression of the second order. From analysis of the transmittance of the layers, it
follows that the band gap of the epitaxial Pb1 − x
Eu
x
Te alloys increases with increasing temperature at x < 0.5 and decreases at x > 0.5. 相似文献
20.
Y. Liang H. Borrmann W. Schnelle J. Goraus J. T. Zhao Yu. Grin 《Journal of Electronic Materials》2010,39(9):1837-1841
A new compound with the filled-skutterudite structure, Ba
x
Pd4Sn
y
Sb12−y
, was prepared by the flux growth and spark plasma sintering (SPS) techniques. The crystal structure was determined from single
crystal and powder x-ray diffraction data. The structure is electronically stabilized by the Sn:Sb ratio, and the lattice
parameters depend on this ratio. For magnetic, electrical conductivity, Hall coefficient, Seebeck coefficient and thermal
conductivity measurements, single crystal and/or SPS-densified specimens were utilized. Ba1.0Pd4Sn7.1Sb5.2 exhibits diamagnetic behavior. The Hall coefficient is negative and increases with temperature. The lattice thermal conductivity
of Ba0.97Pd4Sn6.90Sb4.97 (SPS-densified) is smaller than for CoSb3, but the thermoelectric figure of merit (ZT) is comparatively low due to the low Seebeck coefficient. 相似文献