共查询到20条相似文献,搜索用时 750 毫秒
1.
O. G. Grushka V. T. Maslyuk S. M. Chupyra O. M. Mysliuk S. V. Bilichuk I. I. Zabolotskiy 《Semiconductors》2012,46(3):312-314
The results of studying the electrical properties of Hg3In2Te6 crystals irradiated with electrons with the energy E
e
= 18 MeV and the dose D = 4 × 1016 cm−2 are reported. It is shown that, irrespective of the charge-carrier concentration in the initial material, the Hg3In2Te6 samples acquire the charge-carrier concentration (1.6–1.8) × 1013 cm−3 after irradiation. The phenomenon of Fermi level pinning in an irradiated material is discussed. The initial charge-carrier
concentration, which remains virtually unchanged after irradiation and which ensures the high radiation resistance of Hg3In2Te6 crystals, corresponds to a compensated material, similar to an intrinsic semiconductor at T > 260 K. 相似文献
2.
L. P. Kazakova K. D. Tsendin E. A. Lebedev D. Arsova I. A. Obukhova 《Semiconductors》2010,44(1):76-78
Charge-carrier transport in Ge20As20S60 films has been studied using the transit time method under low-injection conditions at room temperature. It was found that
drift mobilities of electrons and holes in Ge20As20S60 films are close to each other, i.e., μ
e
≈ μ
h
≈ 2 × 10−3 cm2 V−1 s−1 at T = 295 K and F = 5 × 104 V/cm. It was shown that the time dependence of the photocurrent during carrier drift and the voltage dependence of the drift
mobility allowed the use of the concept of anomalous dispersive transport. Experimental data were explained using the model
of transport controlled by carrier trapping by localized states with energy distribution near conduction and valence band
edges described by the exponential law with a characteristic energy of ∼0.05 eV. 相似文献
3.
É. A. Lebedev S. A. Kozykhin N. N. Konstantinova L. P. Kazakova 《Semiconductors》2009,43(10):1343-1346
Effect of high electric fields on the conductivity of 0.5-1-μm-thick layers of a chalcogenide glassy semiconductor with a
composition Ge2Sb2Te5, used in phase memory cells, has been studied. It was found that two dependences are observed in high fields: dependence
of the current I on the voltage U, of the type I ∝ U
n
, with the exponent (n ≈ 2) related to space-charge-limited currents, and a dependence of the conductivity σ on the field strength F of the type σ = σ0exp(F/F
0) (where F
0 = 6 × 104 V cm−1), caused by ionization of localized states. A mobility of 10−3–10−2 cm2 V−1 s−1 was determined from the space-charge-limited currents. 相似文献
4.
The Seebeck coefficient, electrical resistivity, and thermal conductivity of Zr3Mn4Si6 and TiMnSi2 were studied. The crystal lattices of these compounds contain relatively large open spaces, and, therefore, they have fairly
low thermal conductivities (8.26 Wm−1 K−1 and 6.63 Wm−1 K−1, respectively) at room temperature. Their dimensionless figures of merit ZT were found to be 1.92 × 10−3 (at 1200 K) and 2.76 × 10−3 (at 900 K), respectively. The good electrical conductivities and low Seebeck coefficients might possibly be due to the fact
that the distance between silicon atoms in these compounds is shorter than that in pure semiconductive silicon. 相似文献
5.
R. M. Sardarly O. A. Samedov A. P. Abdullayev F. T. Salmanov O. Z. Alekperov E. K. Huseynov N. A. Aliyeva 《Semiconductors》2011,45(11):1387-1390
The temperature dependences of the conductivity σ(T) and the switching and memory effects in one-dimensional TlInSe2 and TlInTe2 single crystals have been studied. A specific feature is found in the dependence σ(T) above 333 K, which is related to the transition of crystals to the state with superionic conductivity. It is suggested that
the ion conductivity is caused by the diffusion of Tl+ ions over vacancies in the thallium sublattice between (In3+Te22−)− and (In3+Se22−)− nanochains (nanorods). S-type switching and memory effects are revealed in TlInSe2 and TlInTe2 crystals, as well as voltage oscillations in the range of negative differential resistance. It is suggested that the switching
effect and voltage oscillations are related to the transition of crystals to the superionic state, which is accompanied by
“melting” of the Tl sublattice. The effect of electric-field-induced transition of TlInSe2 and TlInTe2 crystals to the superionic state is found. 相似文献
6.
Current-voltage characteristics of the In-ZnGa2Se4-In structure have been studied in the temperature range of 90–335 K. Based on the data calculated for the concentration of
three trap types in ZnGa2Se4, the values N
t
= 1.4 × 1013, 8.2 × 1012, and 2.6 × 1012 cm−3 are obtained. The contact region transparency D
k
*= 10−5, surface recombination velocity S
k
= 0.65 m/s, and carrier lifetime τ = 1.5 × 10−4 s were determined. It was found that the current transmission mechanism in electric fields weaker than 103 V/cm is caused by monopolar carrier injection. 相似文献
7.
Colby L. Heideman Raimar Rostek Michael D. Anderson Andrew A. Herzing Ian M. Anderson David C. Johnson 《Journal of Electronic Materials》2010,39(9):1476-1481
An ultralow-thermal-conductivity compound with the ideal formula [(PbSe)1.00]1[MoSe2]1 has been successfully crystallized across a range of compositions. The lattice parameters varied from 1.246 nm to 1.275 nm,
and the quality of the observed 00ℓ diffraction patterns varied through the composition region where the structure crystallized. Measured resistivity values
ranged over an order of magnitude, from 0.03 Ω m to 0.65 Ω m, and Seebeck coefficients ranged from −181 μV K−1 to 91 μV K−1 in the samples after the initial annealing to form the basic structure. Annealing of samples under a controlled atmosphere
of selenium resulted in low conductivities and large negative Seebeck coefficients, suggesting an n-doped semiconductor. Scanning transmission electron microscopy cross-sections confirmed the interleaving of bilayers of PbSe
with Se-Mo-Se trilayers. High-angle annular dark-field images revealed an interesting volume defect, where PbSe grew through
a region where a layer of MoSe2 would be expected in the perfect structure. Further studies are required to correlate the density of these defects with the
observed electrical properties. 相似文献
8.
B. N. Pantha R. Dahal J. Li J. Y. Lin H. X. Jiang G. Pomrenke 《Journal of Electronic Materials》2009,38(7):1132-1135
We report on the experimental investigation of the potential of InGaN alloys as thermoelectric (TE) materials. We have grown
undoped and Si-doped In0.3Ga0.7N alloys by metalorganic chemical vapor deposition and measured the Seebeck coefficient and electrical conductivity of the
grown films with the aim of maximizing the power factor (P). It was found that P decreases as electron concentration (n) increases. The maximum value for P was found to be 7.3 × 10−4 W/m K2 at 750 K in an undoped sample with corresponding values of Seebeck coefficient and electrical conductivity of 280 μV/K and 93␣(Ω cm)−1, respectively. Further enhancement in P is expected by improving the InGaN material quality and conductivity control by reducing background electron concentration. 相似文献
9.
Chunya Wu Zhiguo Meng Shuyun Zhao Shaozhen Xiong Man Wong Hoi Sing Kwok 《Journal of Electronic Materials》2007,36(9):1160-1165
By using an aqueous solution of Ni(NO3)2/NH4OH for formation of Ni media on a-Si, disk-like super-large domain metal-induced radially crystallized (S-MIRC) poly-Si was
prepared. The process requires no buffer layer deposition on a-Si. The prepared S-MIRC poly-Si has an average domain size
of up to 60 μm, highest hole Hall mobility of 27.1 cm2 V−1 s−1, and highest electron Hall mobility of 45.6 cm2 V−1 s−1. Poly-Si TFT made on super-large-domain S-MIRC poly-Si had high mobility of ~105.8 cm2 V−1 s−1, steep sub-threshold slope of ~1.0 V decade−1, high on/off state current ratio of >107 and low threshold voltage of ~ −6.9 V. A simultaneous Ni-collected and induced crystallization model is proposed to explain
the growth kinetics of S-MIRC poly-Si. 相似文献
10.
Yong Liu Yuan-Hua Lin Jinle Lan Bo-Ping Zhang Wei Xu Ce-Wen Nan Hongmin Zhu 《Journal of Electronic Materials》2011,40(5):1083-1086
Polycrystalline In2O3 ceramics co-doped with Zn and Nd were prepared by the spark plasma sintering (SPS) process, and microstructure and thermoelectric
(TE) transport properties of the ceramics were investigated. Our results indicate that co-doping with Zn2+ and Nd3+ shows a remarkable effect on the transport properties of In2O3-based ceramics. Large electrical conductivity (~130 S cm−1) and thermopower (~220 μV K−1) can be observed in these In2O3-based ceramic samples. The maximum power factor (PF) reaches 5.3 × 10−4 W m−1 K−2 at 973 K in the In1.92Nd0.04Zn0.04O3 sample, with a highest ZT of ~0.25. 相似文献
11.
Electronic properties and deep traps in electron-irradiated <Emphasis Type="Italic">n</Emphasis>-GaN
V. N. Brudnyi S. S. Verevkin A. V. Govorkov V. S. Ermakov N. G. Kolin A. V. Korulin A. Ya. Polyakov N. B. Smirnov 《Semiconductors》2012,46(4):433-439
The study is concerned with the effect of electron irradiation (with the energies E = 7 and 10 MeV and doses D = 1016−1018 cm−2) and subsequent heat treatments in the temperature range 100–1000°C on the electrical properties and the spectrum of deep
traps of undoped (concentration of electrons n = 1 × 1014−1 × 1016 cm−3), moderately Si-doped (n = (1.2−2) × 1017 cm−3), and heavily Si-doped (n = (2−3.5) × 1018 cm−3) epitaxial n-GaN layers grown on Al2O3 substrates by metal-organic chemical vapor deposition. It is found that, on electron irradiation, the resistivity of n-GaN increases, this is due to a shift of the Fermi level to the limiting position close to E
c
−0.91 eV. The spectrum of deep traps is studied for the initial and electron-irradiated n-GaN. It is shown that the initial properties of the irradiated material are restored in the temperature range 100–1000°C,
with the main stage of the annealing of radiation defects at about 400°C. 相似文献
12.
Wei Liu Qiang Zhang Xinfeng Tang Han Li Jeff Sharp 《Journal of Electronic Materials》2011,40(5):1062-1066
Mg2(Si0.3Sn0.7)1−y
Sb
y
(0 ≤ y ≤ 0.04) solid solutions were prepared by a two-step solid-state reaction method combined with the spark plasma sintering
technique. Investigations indicate that the Sb doping amount has a significant impact on the thermoelectric properties of
Mg2(Si0.3Sn0.7)1−y
Sb
y
compounds. As the Sb fraction y increases, the electron concentration and electrical conductivity of Mg2(Si0.3Sn0.7)1−y
Sb
y
first increase and then decrease, and both reach their highest value at y = 0.025. The sample with y = 0.025, possessing the highest electrical conductivity and one of the higher Seebeck coefficient values among all the samples,
has the highest power factor, being 3.45 mW m−1 K−2 to 3.69 mW m−1 K−2 in the temperature range of 300 K to 660 K. Meanwhile, Sb doping can significantly reduce the lattice thermal conductivity
(κ
ph) of Mg2(Si0.3Sn0.7)1−y
Sb
y
due to increased point defect scattering, and κ
ph for Sb-doped samples is 10% to 20% lower than that of the nondoped sample for 300 K < T < 400 K. Mg2(Si0.3Sn0.7)0.975Sb0.025 possesses the highest power factor and one of the lower κ
ph values among all the samples, and reaches the highest ZT value: 1.0 at 640 K. 相似文献
13.
Reflectance spectra of single crystals of Bi2Te3-Sb2Te3 solid solutions containing 0, 10, 25, 40, 50, 60, 65, 70, 80, 90, 99.5, and 100 mol % of Sb2Te3 have been studied in the range of 400–4000 cm−1 at the temperature T = 291 K and with orientation of the vector of the electric-field strength E perpendicular to the trigonal axis of the crystal C
3 (E ⊥ C
3). The shape of the spectra is characteristic of plasma reflection; the spectra include the features in the range 1250–3000
cm−1 corresponding to the optical band gap E
g opt. The features become more pronounced as the content of Bi2Te3 is increased to 80 mol % in the composition of the Bi2Te3-Sb2Te3 solid solution. A further increase in the content of Sb2Te3 is accompanied by discontinuities in the functional dependences of the parameters characterizing the plasma oscillations
of free charge carriers on the solid-solution composition and also by a sharp increase in E
g opt. 相似文献
14.
Thermoelectric materials are attractive since they can recover waste heat directly in the form of electricity. In this study,
the thermoelectric properties of ternary rare-earth sulfides LaGd1+x
S3 (x = 0.00 to 0.03) and SmGd1+x
S3 (x = 0.00 to 0.06) were investigated over the temperature range of 300 K to 953 K. These sulfides were prepared by CS2 sulfurization, and samples were consolidated by pressure-assisted sintering to obtain dense compacts. The sintered compacts
of LaGd1+x
S3 were n-type metal-like conductors with a thermal conductivity of less than 1.7 W K−1 m−1. Their thermoelectric figure of merit ZT was improved by tuning the chemical composition (self-doping). The optimized ZT value of 0.4 was obtained in LaGd1.02S3 at 953 K. The sintered compacts of SmGd1+x
S3 were n-type hopping conductors with a thermal conductivity of less than 0.8 W K−1 m−1. Their ZT value increased significantly with temperature. In SmGd1+x
S3, the ZT value of 0.3 was attained at 953 K. 相似文献
15.
R. M. Sardarli O. A. Samedov A. P. Abdullayev E. K. Huseynov E. M. Qocayev F. T. Salmanov 《Semiconductors》2011,45(8):975-979
Temperature dependences of electrical conductivity σ(T) and permittivity ɛ(T) of one-dimensional (1D) TlGaTe2 single crystals are investigated. At temperatures higher than 305 K, superionic conductivity of the TlGaTe2 is observed and is related to diffusion of Tl+ ions via vacancies in the thallium sublattice between (Ga3+Te22−
− nanochains. A relaxation character of dielectric anomalies is established, which suggests the existence of electric charges
weakly bound to the crystal lattice. Upon the transition to the superionic state, relaxors in the TlGaTe2 crystals are Tl+ dipoles ((Ga3+Te22−)− chains) that arise due to melting of the thallium sublattice and hops of Tl+ ions from one localized state to another. The effect of a field-induced transition of the TlGaTe2 crystal to the superionic state is detected. 相似文献
16.
A PbTiO3/Ba0.85Sr0.15TiO3/PbTiO3 (PT/BST15/PT) sandwich thin film has been prepared on Pt/Ti/SiO2/Si substrates by an improved sol-gel technique. It is found that such films under rapid thermal annealing at 700°C crystallize
more favorably with the addition of a PbTiO3 layer. They possess a pure, perovskite-phase structure with a random orientation. The polarization-electric field (P-E) hysteresis
loop and current-voltage (I-V) characteristic curves reveal that a PT/BST15/PT film exhibits good ferroelectricity at room
temperature. However, no sharp peak, only a weak maximum, is observed in the curves of the dielectric constant versus temperature.
The dielectric constant, loss tangent, leakage current density at 20 kV/cm, remnant polarization, and coercive field of the
PT/BST15/PT film are 438, 0.025, 1.3 × 10−6 Acm−2, 2.46 μCcm−2, and 41 kVcm−1, respectively, at 25°C and 10 kHz. The PT/BST15/PT film is a candidate material for high sensitivity elements for uncooled,
infrared, focal plane arrays (UFPAs) to be used at near ambient temperature. 相似文献
17.
K.K. Allums M. Hlad A.P. Gerger B.P. Gila C.R. Abernathy S.J. Pearton F. Ren R. Dwivedi T.N. Fogarty R. Wilkins 《Journal of Electronic Materials》2007,36(4):519-523
Proton irradiation of Sc2O3/GaN and Sc2O3/MgO/GaN metal-oxide semiconductor diodes was performed at two energies, 10 MeV and 40 MeV, and total fluences of 5 × 109 cm−2, corresponding to 10 years in low-earth orbit. The proton damage causes a decrease in forward breakdown voltage and a flat-band
voltage shift in the capacitance-voltage characteristics, indicating a change in fixed oxide charge and damage to the dielectric.
The interface state densities after irradiation increased from 5.9 × 1011 cm−2 to 1.03 × 1012 cm−2 in Sc2O3/GaN diodes and from 2.33 × 1011 to 5.3 × 1011 cm−2 in Sc2O3/MgO/GaN diodes. Postannealing at 400°C in forming gas recovered most of the original characteristics but did increase the
interfacial roughness. 相似文献
18.
C. Navone M. Soulier M. Plissonnier A. L. Seiler 《Journal of Electronic Materials》2010,39(9):1755-1759
In major applications, optimal power will be achieved when thermoelectric films are at least 100 μm thick. In this paper we demonstrate that screen-printing is an ideal method to deposit around 100 μm of (Bi,Sb)2(Te,Se)3-based films on a rigid or flexible substrate with high Seebeck coefficient value (90 μV K−1 to 160 μV K−1) using a low-temperature process. Conductive films have been obtained after laser annealing and led to acceptable thermoelectric
performance with a power factor of 0.06 μW K−2 cm−1. While these initial material properties are not at the level of bulk materials, the complete manufacturing process is cost-effective,
compatible with large surfaces, and affords a mass-production technique. 相似文献
19.
Ternary rare-earth sulfides NdGd1+x
S3, where 0 ≤ x ≤ 0.08, were prepared by sulfurizing Ln2O3 (Ln = Nd, Gd) with CS2 gas, followed by reaction sintering. The sintered samples have full density and homogeneous compositions. The Seebeck coefficient,
electrical resistivity, and thermal conductivity were measured over the temperature range of 300 K to 950 K. All the sintered
samples exhibit a negative Seebeck coefficient. The magnitude of the Seebeck coefficient and the electrical resistivity decrease
systematically with increasing Gd content. The thermal conductivity of all the sintered samples is less than 1.9 W K−1 m−1. The highest figure of merit ZT of 0.51 was found in NdGd1.02S3 at 950 K. 相似文献
20.
W. Shin T. Nakashima M. Nishibori T. Itoh N. Izu I. Matsubara Y. Nakagawa A. Yamamoto H. Obara 《Journal of Electronic Materials》2011,40(5):817-822
The performance of a microcombustor thermoelectric generator device based on a thermopile using p-type Bi0.3Sb1.7Te3 (BST) and n-type Pt films has been investigated. The BST films were prepared by two different methods—pulsed laser deposition (PLD) and
sputter deposition—on Si3N4/SiO2 multilayers on Si substrate. The ceramic catalyst combustor was patterned on the thermopile end on a thin membrane fabricated
by back-side bulk etching of the silicon substrate. At 138°C the thermoelectric power factors of the PLD and sputter-deposited
films were 3.6 × 10−3 W/mK2 and 0.22 × 10−3 W/mK2, respectively. The power from the generator with the sputter-deposited film was 0.343 μW, which was superior to that of the device with the PLD film, which provided 0.1 μW, for combustion of a 200 sccm flow of 3 v/v% hydrogen in air. 相似文献