共查询到20条相似文献,搜索用时 31 毫秒
1.
M. N. Solovan A. I. Mostovyi V. V. Brus E. V. Maistruk P. D. Maryanchuk 《Semiconductors》2016,50(8):1020-1024
n-TiN/p-Hg3In2Te6 heterostructures are fabricated by depositing a thin n-type titanium nitride (TiN) film onto prepared p-type Hg3In2Te6 plates using reactive magnetron sputtering. Their electrical and photoelectric properties are studied. Dominant charge-transport mechanisms under forward bias are analyzed within tunneling-recombination and tunneling models. The fabricated n-TiN/p-Hg3In2Te6 structures have the following photoelectric parameters at an illumination intensity of 80 mW/cm2: the open-circuit voltage is VOC = 0.52 V, the short-circuit current is ISC = 0.265 mA/cm2, and the fill factor is FF = 0.39. 相似文献
2.
M. N. Solovan G. O. Andrushchak A. I. Mostovyi T. T. Kovaliuk V. V. Brus P. D. Maryanchuk 《Semiconductors》2018,52(2):236-241
Graphite/p-SiC Schottky diodes are fabricated using the recently suggested technique of transferring drawn graphite films onto p-SiC single-crystal substrates. The current–voltage and capacitance–voltage characteristics are measured at different temperatures and at different frequencies of a small-signal AC signal, respectively. The temperature dependences of the potential-barrier height and of the series resistance of the graphite/p-SiC junctions are measured and analyzed. The dominant mechanisms of the charge–carrier transport through the diodes are determined. It is shown that the dominant mechanisms of the transport of charge carriers through the graphite/p-Si Schottky diodes at a forward bias are multi-step tunneling recombination and tunneling described by the Newman formula (at high bias voltages). At reverse biases, the dominant mechanisms of charge transport are the Frenkel–Poole emission and tunneling. It is shown that the graphite/p-SiC Schottky diodes can be used as detectors of ultraviolet radiation since they have the open-circuit voltage Voc = 1.84 V and the short-circuit current density Isc = 2.9 mA/cm2 under illumination from a DRL 250-3 mercury–quartz lamp located 3 cm from the sample. 相似文献
3.
V. S. Varavin V. V. Vasilyev A. A. Guzev S. A. Dvoretsky A. P. Kovchavtsev D. V. Marin I. V. Sabinina Yu. G. Sidorov G. Yu. Sidorov A. V. Tsarenko M. V. Yakushev 《Semiconductors》2016,50(12):1626-1629
The parameters of multilayer CdxHg1–xTe heterostructures for photodetectors operating at wavelengths of up to 5 μm, grown by molecular-beam epitaxy (MBE) on silicon substrates, are studied. The passivating properties of thin CdTe layers on the surface of these structures are analyzed by measuring the C–V characteristics. The temperature dependences of the minority carrier lifetime in the photoabsorption layer after growth and thermal annealing are investigated. Samples of p +–n-type photodiodes are fabricated by the implantation of arsenic ions into n-type layers, doped with In to a concentration of (1–5) × 1015 cm–3. The temperature dependences of the reverse currents are measured at several bias voltages; these currents turn out to be almost two orders of magnitude lower than those for n +–p-type diodes. 相似文献
4.
The results of an experimental study of the capacitance–voltage (C–V) characteristics and deep-level transient spectroscopy (DLTS) spectra of p+–p0–i–n0 homostructures based on undoped dislocationfree GaAs layers and InGaAs/GaAs and GaAsSb/GaAs heterostructures with homogeneous networks of misfit dislocations, all grown by liquid-phase epitaxy (LPE), are presented. Deep-level acceptor defects identified as HL2 and HL5 are found in the epitaxial p0 and n0 layers of the GaAs-based structure. The electron and hole dislocation-related deep levels, designated as, respectively, ED1 and HD3, are detected in InGaAs/GaAs and GaAsSb/GaAs heterostructures. The following hole trap parameters: thermal activation energies (E t ), capture cross sections (σ p ), and concentrations (N t ) are calculated from the Arrhenius dependences to be E t = 845 meV, σ p = 1.33 × 10–12 cm2, N t = 3.80 × 1014 cm–3 for InGaAs/GaAs and E t = 848 meV, σ p = 2.73 × 10–12 cm2, N t = 2.40 × 1014 cm–3 for GaAsSb/GaAs heterostructures. The concentration relaxation times of nonequilibrium carriers are estimated for the case in which dislocation-related deep acceptor traps are involved in this process. These are 2 × 10–10 s and 1.5 × 10–10 s for, respectively, the InGaAs/GaAs and GaAsSb/GaAs heterostructures and 1.6 × 10–6 s for the GaAs homostructures. 相似文献
5.
CdTe thin films of 500 Å thickness prepared by thermal evaporation technique were analyzed for leakage current and conduction mechanisms. Metal–insulator–metal (MIM) capacitors were fabricated using these films as a dielectric. These films have many possible applications, such as passivation for infrared diodes that operate at low temperatures (80 K). Direct-current (DC) current–voltage (I–V) and capacitance–voltage (C–V) measurements were performed on these films. Furthermore, the films were subjected to thermal cycling from 300 K to 80 K and back to 300 K. Typical minimum leakage currents near zero bias at room temperature varied between 0.9 nA and 0.1 μA, while low-temperature leakage currents were in the range of 9.5 pA to 0.5 nA, corresponding to resistivity values on the order of 108 Ω-cm and 1010 Ω-cm, respectively. Well-known conduction mechanisms from the literature were utilized for fitting of measured I–V data. Our analysis indicates that the conduction mechanism in general is Ohmic for low fields <5 × 104 V cm?1, while the conduction mechanism for fields >6 × 104 V cm?1 is modified Poole–Frenkel (MPF) and Fowler–Nordheim (FN) tunneling at room temperature. At 80 K, Schottky-type conduction dominates. A significant observation is that the film did not show any appreciable degradation in leakage current characteristics due to the thermal cycling. 相似文献
6.
I. G. Orletsky M. I. Ilashchuk V. V. Brus P. D. Marianchuk M. M. Solovan Z. D. Kovalyuk 《Semiconductors》2016,50(3):334-338
The conditions for fabricating photosensitive TiN/p-InSe heterojunctions by the reactive-magnetron sputtering of thin titanium-nitride films onto freshly cleaved p-InSe single-crystal substrates is investigated. The presence of a tunnel-transparent high-resistivity In2Se3 layer at the heterojunction is revealed from analysis of the I–V characteristics, and the effect of this layer on the electrical properties and photosensitivity spectra of the heterostructures is analyzed. The dominant current transport mechanisms through the TiN/p-InSe energy barrier under forward and reverse bias are determined. 相似文献
7.
For an NMOS structure with 3.7-nm-thick oxide, dynamic I-V characteristics are digitally measured by applying an upward and a downward gate-voltage ramp. An averaging procedure is employed to deduce the tunneling (active) current component and the quasi-static C-V characteristic (CVC). Analyzing the depletion segment of the CVC provides reliable values of the semiconductor doping level, the oxide capacitance and thickness, and the sign and density of oxide-fixed charge, as well as estimates of the dopant concentration in the poly-Si region. These data are used to identify the Ψs(V g), V i(V g), and I t(V i) characteristics, where Ψs is the n-Si surface potential, V i is the voltage drop across the oxide, V g is the gate voltage, and I t is the tunneling current; the gate-voltage range explored extends to prebreakdown fields (~13 MV cm?1). The results are obtained without recourse to fitting parameters and without making any assumptions as to the energy spectrum of electrons tunneling from the n-Si deep-accumulation region through the oxide. It is believed that experimental I t-V i and Ψs-V g characteristics will provide a basis for developing a theory of tunneling covering not only the degeneracy and size quantization of the electron gas in the semiconductor but also the nonclassical profile of the potential barrier to electron tunneling associated with the oxide-fixed charge. 相似文献
8.
The effect of annealing in argon at temperatures of Tan = 700–900°C on the I–V characteristics of metal–Ga2O3–GaAs structures is investigated. Samples are prepared by the thermal deposition of Ga2O3 powder onto GaAs wafers with a donor concentration of N d = 2 × 1016 cm–3. To measure theI–V characteristics, V/Ni metal electrodes are deposited: the upper electrode (gate) is formed on the Ga2O3 film through masks with an area of S k = 1.04 × 10–2 cm2 and the lower electrode in the form of a continuous metallic film is deposited onto GaAs. After annealing in argon at Tan ≥ 700°C, the Ga2O3-n-GaAs structures acquire the properties of isotype n-heterojunctions. It is demonstrated that the conductivity of the structures at positive gate potentials is determined by the thermionic emission from GaAs to Ga2O3. Under negative biases, current growth with an increase in the voltage and temperature is caused by field-assisted thermal emission in gallium arsenide. In the range of high electric fields, electron phonon-assisted tunneling through the top of the potential barrier is dominant. High-temperature annealing does not change the electron density in the oxide film, but affects the energy density of surface states at the GaAs–Ga2O3 interface. 相似文献
9.
A. E. Belyaev N. S. Boltovets V. N. Ivanov V. P. Klad’ko R. V. Konakova Ya. Ya. Kudrik A. V. Kuchuk V. V. Milenin Yu. N. Sveshnikov V. N. Sheremet 《Semiconductors》2008,42(6):689-693
A mechanism of charge transport in Au-TiB x -n-GaN Schottky diodes with a space charge region considerably exceeding the de Broglie wavelength in GaN is studied. Analysis of temperature dependences of current-voltage (I–V) characteristics of forward-biased Schottky barriers showed that, in the temperature range 80–380 K, the charge transport is performed by tunneling along dislocations intersecting the space charge region. Estimation of dislocation density ρ by the I–V characteristics, in accordance with a model of tunneling along the dislocation line, gives the value ρ ≈ 1.7 × 107 cm?2, which is close in magnitude to the dislocation density measured by X-ray diffractometry. 相似文献
10.
I. O. Maiboroda J. V. Grishchenko I. S. Ezubchenko I. S. Sokolov I. A. Chernych A. A. Andreev M. L. Zanaveskin 《Semiconductors》2018,52(6):776-782
The nonlinear behavior of the I–V characteristics of symmetric contacts between a metal and degenerate n-GaN, which form oppositely connected Schottky diodes, is investigated at free-carrier densities from 1.5 × 1019 to 2.0 × 1020 cm–3 in GaN. It is demonstrated that, at an electron density of 2.0 × 1020 cm–3, the conductivity between metal (chromium) and GaN is implemented via electron tunneling and the resistivity of the Cr–GaN contact is 0.05 Ω mm. A method for determining the parameters of potential barriers from the I–V characteristics of symmetric opposite contacts is developed. The effect of pronounced nonuniformity of the current density and voltage distributions over the contact area at low contact resistivity is taken into account. The potential-barrier height for Cr–n+-GaN contacts is found to be 0.47 ± 0.04 eV. 相似文献
11.
N. T. Bagraev L. E. Klyachkin A. M. Malyarenko A. I. Ryskin A. S. Shcheulin 《Semiconductors》2005,39(5):528-532
Boron diffusion and the vapor-phase deposition of silicon layers are used to prepare ultrashallow p+-n junctions and p+-Si-n-CdF2 heterostructures on an n-CdF2 crystal surface. Forward portions of the I–V characteristics of the p+-n junctions and p+-Si-n-CdF2 heterojunctions reveal the CdF2 band gap (7.8 eV), as well as allow the identification of the valence-band structure of cadmium fluoride crystals. Under conditions in which forward bias is applied to the p+-Si-n-CdF2 heterojunctions, electroluminescence spectra are measured for the first time in the visible spectral region. 相似文献
12.
The results of the development of power switching transistors based on epitaxial gallium nitride heterostructures to create an energy-efficient conversion technique are presented. The developed powerful GaN transistor operates in enrichment mode with unlocking threshold voltage V th = +1.2 V and a maximum drain-source current I ds = 0.15 A/mm at the drain-source voltage V ds = +8 V. The drain-source breakdown voltage in the closed state is V b = 300 V at the drain-source distance L ds = 8.5 μm and drain-source voltage V ds = 0 V. 相似文献
13.
Hydrogenated silicon (Si:H) layers and Si:H/p-Si heterostructures were produced by multiple-energy (3–24 keV) high-dose (5×1016–3×1017 cm?2) hydrogen implantation into p-Si wafers. After implantation, current transport across the structures is controlled by the Poole-Frenkel mechanism, with the energy of the dominating emission center equal to E c ?0.89 eV. The maximum photosensitivity is observed for structures implanted with 3.2×1017 cm?2 of hydrogen and annealed in the temperature range of 250–300°C. The band gap of the Si:H layer E g ≈2.4 eV, and the dielectric constant ?≈3.2. The density of states near the Fermi level is (1–2)×1017 cm?3 eV?1. 相似文献
14.
The electroluminescence characteristics of a single type-II p-Ga0.84In0.16As0.22Sb0.78/n-In0.83Ga0.17As0.80Sb0.20 heterostructure have been studied in the temperature range 77–300 K. A new advanced laser structure based on a type-II broken-gap p-GaInAsSb/n-InGaAsSb heterojunction as the active region has been suggested and fabricated. Single-mode lasing at wavelength λ=3.14 µm under a threshold current density jth=400 A/cm2 (T=77 K) was obtained. The domination of TM-over TE-polarization, observed both in the spontaneous and coherent modes of operation of the novel laser structure, can be accounted for by involvement of light holes, tunneling across the heterointerface, in radiative recombination. 相似文献
15.
T. A. Pagava 《Semiconductors》2007,41(6):631-633
p-Si single crystals grown by the Czochralski method were studied; the hole concentration in these crystals was p = 6 × 1013 cm?3. The samples were irradiated with 8-MeV electrons at 300 K and were then annealed isochronously in the temperature range T ann = 100–500°C. The studies were carried out using the Hall method in the temperature range of 77–300 K. It is shown that annealing of divacancies occurs via their transformation into the B s V 2 complexes. This complex introduces the energy level located at E v + 0.22 eV into the band gap and is annealed out in the temperature range of 360–440°C. It is assumed that defects with the level E v + 0.2 eV that anneal out in the temperature range T ann = 340–450°C are multicomponent complexes and contain the atoms of the doping and background impurities. 相似文献
16.
The distribution of charged centers N(w), quantum efficiency, and electroluminescence spectra of blue and green light-emitting diodes (LED) based on InGaN/AlGaN/GaN p-n heterostructures were investigated. Multiple InGaN/GaN quantum wells (QW) were modulation-doped with Si donors in GaN barriers. Acceptor and donor concentrations near the p-n junction were determined by the heterodyne method of dynamic capacitance to be about N A ≥ 1 × 1019 cm?3 ? N D ≥ 1 × 1018 cm?3. The N(w) functions exhibited maxima and minima with a period of 11–18 (±2–3 nm) nm. The energy diagram of the structures has been constructed. The shifts of spectral peaks with variation of current (J=10?6–3×10?2 A) are smaller (13–12 meV for blue and 20–50 meV for green LEDs) than the corresponding values for the diodes with undoped barriers (up to 150 meV). This effect is due to the screening of piezoelectric fields in QWs by electrons. The dependence of quantum efficiency on current correlates with the charge distribution and specific features in the current-voltage characteristics. 相似文献
17.
The electron transport through single-barrier GaAs/AlAs/GaAs heterostructures is studied. This transport is caused by resonant tunneling between the two-dimensional states related to the Γ valley of the GaAs conduction band and various two-or zero-dimensional donor states related to the lower X valleys of the AlAs conduction band. The resonant electron tunneling both via various two-dimensional states related to the Xz and Xxy valleys in AlAs (the Xz and Xxy states) and via related states of Si donors X z D and X xy D was observed. This circumstance made it possible to determine the binding energies of these states (EB(X z D )≈50 meV and EB(X xy D )≈70 meV, respectively) directly from the results of identification of resonance features in transport characteristics. An analysis of the structure of experimental resonances corresponding to tunneling between the Γ and X Landau levels in a magnetic field made it possible to determine the transverse effective mass in the X valleys of AlAs (mt=(0.2±0.02)m0). An additional fine structure of donor resonances is observed in experimental transport characteristics. This fine structure is caused by resonant tunneling of electrons through the states of the donors that are located in various atomic layers of the AlAs barrier (in the growth direction) and therefore have different binding energies. 相似文献
18.
The phenomenon of terahertz radiation detection by resonant tunneling structures (RTSs) has been studied. The calculations of the changes ΔI0 in the direct current (DC) component I0 under the action of an alternating electric field were carried out by the solution of a nonstationary Schrodinger equation with a time-periodic electric field based on the Floquet mode expansion of the wave functions. The dependences of the DC component I0 in resonant tunneling structures on the frequency ν and AC signal amplitude Vac have been built. It is shown that the ΔI0 value in triple-barrier RTSs at resonance frequency hv ≈ Er2–Er1 (Er1 and Er2 are the energies of the size-quantized levels) can exceed a low-frequency value by more than an order of magnitude. The parameters of the structures have been optmized, in order to use them in the terahertz radiation detectors in the anbsence of an external bias. The possibility of tuning the resonance frequency in the terahertz range by changing the DC bias has been shown. 相似文献
19.
S. Yu. Paranchych L. D. Paranchych V. N. Makogonenko Yu. V. Tanasyuk M. D. Andriichuk V. R. Romanyuk 《Semiconductors》2005,39(6):712-715
CdTe:(V, Ge) single crystals are grown using the Bridgman-Stockbarger method. The impurity concentrations in the melt are NV = 1 × 1019 cm?3 and NGe = 5 × 1018 and 1 × 1019 cm?3. Electrical and galvanomagnetic characteristics are studied in the temperature range 300–400 K. It is found that the equilibrium characteristics are governed by deep levels (ΔE = 0.75–0.95 eV) located close to the midgap. Low-temperature optical absorption spectra indicate that the impurity levels of V and Ge ions in the low-energy region are in different charge states. In addition, the samples are annealed in Cd vapor and then rapidly cooled. This annealing causes the decomposition of various complexes formed during the crystal growth and an increase in both electrical conductivity and charge carrier concentration. 相似文献
20.
B. A. Komarov 《Semiconductors》2004,38(9):1041-1046
Deep-level transient spectroscopy is used to study the formation of complexes that consist of a radiation defect and a residual impurity atom in silicon. It is established that heat treatment of the diffused Si p+-n junctions irradiated with fast electrons lead to the activation of a residual Fe impurity and the formation of the FeVO (E0.36 trap) and FeV2 (H0.18 trap) complexes. The formation of these traps is accompanied by the early (100–175°C) stage of annealing of the main vacancy-related radiation defects: the A centers (VO) and divacancies (V2). The observed complexes are electrically active and introduce new electron (E0.36: E t e =E c -0.365 eV, σ n =6.8×10?15 cm2) and hole (H0.18: E t h =E v +0.184 eV, σ p =3.0×10?15 cm2) levels into the silicon band gap and have a high thermal stability. It is believed that the complex FeVO corresponds to the previously observed and unidentified defects that have an ionization energy of E t e =E c ?(0.34–0.37) eV and appear as a result of heat treatment of irradiated diffused Si p+-n junctions. 相似文献