scholarly journals Электрические свойства и энергетические параметры гетеропереходов n-FeS-=SUB=-2-=/SUB=-/p-Cd-=SUB=-1-x-=/SUB=-Zn-=SUB=-x-=/SUB=-Te

2018 ◽  
Vol 52 (9) ◽  
pp. 1049
Author(s):  
И.Г. Орлецкий ◽  
М.И. Илащук ◽  
М.Н. Солован ◽  
П.Д. Марьянчук ◽  
О.А. Парфенюк ◽  
...  
Keyword(s):  
Space Charge ◽  
Spray Pyrolysis ◽  
Space Charge Region ◽  
Energy Levels ◽  
Reverse Current ◽  
Comprehensive Analysis ◽  
Energy Profile ◽  
Good Correspondence ◽  
Current Voltage ◽  
Capacitance Voltage

AbstractThe conditions for fabricating n -FeS_2/ p -Cd_1 –_ x Zn_ x Te heterojunctions by the spray pyrolysis of thin pyrite films on p -Cd_1 –_ x Zn_ x Te crystalline substrates are investigated. A comprehensive analysis of the current–voltage ( I – V ) and capacitance–voltage ( C – V ) characteristics makes it possible to establish the limitation of the reverse current by the space-charge region at small reverse biases and consider the mechanisms of current formation with the participation of energy levels near the heterojunction. A model of the energy profile of the n -FeS_2/ p -Cd_1 –_ x Zn_ x Te heterojunction is proposed, which turns out to be in good correspondence with the experimentally determined parameters and the dynamics of their change with a variation in temperature.

Recombination and Excess Currents in 4H-SiC Structure with Low-Doped n-Region

2013 ◽  
Vol 740-742 ◽  
pp. 565-568 ◽  
Author(s):  
Anatoly M. Strel'chuk ◽  
Evgenia V. Kalinina
Keyword(s):  
Space Charge ◽  
Space Charge Region ◽  
Deep Level ◽  
Reverse Current ◽  
Effective Lifetime ◽  
Current Voltage ◽  
Temperature Dependences ◽  
Barrier Type ◽  
Current Voltage Characteristics ◽  
Increasing Temperature

Presented in this paper are the results of a study of forward and reverse current-voltage characteristics of the 4H-SiC pn structures produced by implantation of Al+ ions in low-doped ((5-7)∙1014cm-3) n-type conductivity epitaxial layer. A forward current was identified which is consistent with the model of recombination in the space charge region of a pn junction via a deep level: J=Joexp(qU/nkT), where Jo=Jo*exp[-Ea/(kT)] (or J= Jo*exp[(qU-2Ea)/nkT)]) with the ideality factor n=2. Parameters of this current are as follows: Jo(293 K) ~ 8∙10-25 A/cm2, Ea 1.73-1.75 eV (2Ea3.46-3.5 eV), Jo*~7∙105 A/cm2. A comparison of the experimental and model-based values of Ea, with allowance for all clearly defined temperature dependences, both strong and weak, of the model of recombination in the space charge region shows that the effective lifetime increases and effective trapping cross section σeff of the recombination level decreases with increasing temperature: σeff ~ T-2÷σeff ~ T-2.5 or σeff ~exp(ΔE /kT) where ΔE=80-100 meV. Reverse current practically in whole temperature range is excess current, only at high temperatures (~800 K) reverse current became close to generation current in space charge region. Special interest are the excess currents as a result of the application of a reverse or forward voltage at high temperature. The barrier type excess currents is characteristic of SiC.

scholarly journals A Study of a-Sic/C-Si(n) Isotype Heterojunctions

1993 ◽  
Vol 16 (1) ◽  
pp. 55-64 ◽  
Author(s):  
N. Georgoulas ◽  
L. Magafas ◽  
A. Thanailakis
Keyword(s):  
Temperature Dependence ◽  
Crystalline Silicon ◽  
Diffusion Mechanism ◽  
Thermionic Emission ◽  
Reverse Current ◽  
Emission Mechanism ◽  
Drift Diffusion ◽  
Si Substrates ◽  
Current Voltage ◽  
Capacitance Voltage

In the present work a study of the electrical properties of heterojunctions between rf sputtered amorphous silicon carbide (a-SiC) thin films and n-type crystalline silicon (c-Si) substrates is reported. The current-voltage (I-V) and capacitance-voltage (C-V) characteristics, as well as the temperature dependence of the current of a-SiC/c-Si(n) heterojunctions were measured. The I-V characteristics of a-SiC/ c-Si(n) heterojunctions exhibit poor rectification properties, with a high reverse current, at higher temperatures (T > 250K), whereas good rectification properties are obtained at lower temperatures (T < 250K). It was found that the a-SiC/c-Si(n) heterojunctions are isotype, suggesting that-the conductivity of a-SiC is n-type. The temperature dependence of the current (from 185K to 320K) showed that the majority carriers of c-Si(n) (i.e. electrons) are transported from c-Si(n) to a-SiC mainly by the thermionic emission mechanism, or by the drift-diffusion mechanism. From C-V measurements of a-SiC/c-Si(n) heterojunctions the electron affinity of a-SiC was found to be X1= 4.20 ± 0.04 eV. Finally, the a-SiC/ c-Si(n) isotype heterojunctions are expected to be interesting devices as infrared

THERMAL CURRENTS FROM UNDOPED SEMI-INSULATING GaAs MONITORED BY CHARGE DEEP-LEVEL TRANSIENT SPECTROSCOPY

1995 ◽  
Vol 09 (23) ◽  
pp. 3099-3114
Author(s):  
I. THURZO ◽  
K. GMUCOVÁ ◽  
F. DUBECKÝ ◽  
J. DARMO
Keyword(s):  
Space Charge ◽  
Space Charge Region ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Energy Levels ◽  
Thermally Stimulated Currents ◽  
Metal Semiconductor Metal ◽  
Transient Spectroscopy ◽  
Electrical Bias

Metal-semiconductor-metal (MSM) devices prepared from crystalline undoped semi-insulating GaAs were investigated by charge deep-level transient spectroscopy (QDLTS), while exciting the devices by electrical bias pulses in dark. Unlike current concepts of the QDLTS response, thermally stimulated currents were integrated from devices with GaAs crystals thinned down to or below 200 µm and equipped with Au electrodes. Au-GaAs-Au structures on 230 µm thick crystals exhibited standard QDLTS response on either cooling or heating between 100 K and 250 K. It is concluded that a macroscopic space charge region of width ≈10−7 m is formed at the Au/GaAs interface, as the dominant energy levels became ionized. Obtained results on the peaks of the thermally stimulated charge were correlated with those of potentially identical peaks observed via optical admittance transient spectroscopy (OATS).

Early-Effect like Behavior in Space Charge Regions of Organic Bulk-Heterojunction Photodiodes

2011 ◽  
Vol 1360 ◽  
Author(s):  
Ali Bilge Guvenc ◽  
Cengiz Ozkan ◽  
Mihrimah Ozkan
Keyword(s):  
Space Charge ◽  
Space Charge Region ◽  
Bulk Heterojunction ◽  
Incident Light ◽  
Bipolar Junction Transistors ◽  
Power Comparison ◽  
Light Power ◽  
Early Effect ◽  
Capacitance Voltage ◽  
Effect Of Light

ABSTRACTThe space charge region width of the Schottky barrier that forms on the interface between aluminum and organic semiconductor polymer of bulk-heterojunction organic photodiodes has been investigated according to reverse voltage bias over the device and the capacitance-voltage characteristics. Here, we investigated the space charge region widths according to incident light power. Comparison of the mathematical models and experimental data measured under different light power indicate that effect of light on the space charge region of photodiodes is similar to the effect of base-emitter voltage on the space charge region of base-emitter junction in bipolar junction transistors.

Electrical Characterization Of Nitrogen Acceptors In p-ZnSe/p-GaAs Grown By Molecular Beam Epitaxy

1996 ◽  
Vol 442 ◽  
Author(s):  
D. Seghier ◽  
H.P. Gislason
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Deep Level ◽  
Energy Levels ◽  
Reverse Current ◽  
Electrical Characterization ◽  
Growth Conditions ◽  
Current Voltage ◽  
Major Interest ◽  
Transient Spectroscopy

AbstractUsing current-voltage measurements, deep-level transient spectroscopy and admittance spectroscopy we investigated nitrogen doped ZnSe grown on p-GaAs substrates by molecular beam epitaxy. Three major hole traps were observed with energy levels at 0. 11, 0.46, and 0.56 eV from the valence band. We attribute the level at 0.11 eV to a nitrogen acceptor. No other direct observations of this important acceptor level in p-ZnSe have been reported in the literature so far. The two remaining levels may originate from the nitrogen doping process. In addition, reverse current-voltage characteristics of the ZnSe/GaAs heterojunction show a hysteresis at low temperature and a soft saturation. At a constant reverse bias the current increases slowly until it reaches a steady state value. This behavior is attributed to a slow voltage-induced barrier lowering due to the presence of mismatch interface states. Therefore, these analyses are of a major interest for applications of ZnSe/GaAs based devices and illustrates the necessity of improving the growth conditions of such structures.

scholarly journals Влияние радиационных дефектов, созданных низкоэнергетическими протонами при температуре 83 K, на характеристики кремниевых фотоэлектрических структур

2020 ◽  
Vol 54 (2) ◽  
pp. 144
Author(s):  
Н.М. Богатов ◽  
Л.Р. Григорьян ◽  
А.И. Коваленко ◽  
М.С. Коваленко ◽  
Ф.А. Колоколов ◽  
...  
Keyword(s):  
Space Charge ◽  
Space Charge Region ◽  
Surface Region ◽  
Initial Energy ◽  
Low Energy ◽  
Radiation Defects ◽  
High Concentration ◽  
Transmission Coefficients ◽  
Current Voltage ◽  
P Type

Irradiation with low-energy protons leads to a change in the electrophysical, optical, and other properties of the surface region of semiconductor structures, which creates additional possibilities for modifying semiconductor devices. The work is devoted to the study of the effect of radiation defects created by low-energy protons at a sample temperature of 83 K on the properties of two-sided silicon photovoltaic structures with a diffusion n^+-p junction. Samples of n^+-p-p^+ type were irradiated with a flux of protons with an energy of 40 keV or 180 keV and a dose of 1015 cm^-2. To explain the observed regularities in the variation of the parameters of the current-voltage characteristics and the transmission coefficients, the distribution of the average number of interstitial silicon, vacancies, divacancies, and disordering regions created under these conditions on the unit projective path length by one proton in the diffusion layer and the space charge region of the n^+-p junction was calculated. It is shown that protons with an initial energy of 40 keV predominantly change the physical properties of a layer with a high concentration of donors, and protons with an initial energy of 180 keV are properties of the space-charge region in a layer containing acceptors. The number of radiation defects in the maximum spatial distribution in the n-region is much smaller than in the p-region.

Annealing Effects on Electrical and Optical Properties of N-ZnO/P-Si Heterojunction Diodes

2011 ◽  
Vol 324 ◽  
pp. 233-236 ◽  
Author(s):  
Sadia Muniza Faraz ◽  
Muhammed Naveed Alvi ◽  
Anne Henry ◽  
Omer Nour ◽  
Magnus Willander ◽  
...  
Keyword(s):  
Ohmic Contacts ◽  
Deep Level ◽  
Reverse Current ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Electrical Characteristics ◽  
Current Voltage ◽  
Aqueous Chemical Growth ◽  
Capacitance Voltage ◽  
Annealing Effects

The effects of post fabrication annealing on the electrical characteristics of n-ZnO/p-Si heterostructure are studied. The nanorods of ZnO are grown by aqueous chemical growth (ACG) technique on p-Si substrate and ohmic contacts of Al/Pt and Al are made on ZnO and Si. The devices are annealed at 400 and 600 °C in air, oxygen and nitrogen ambient. The characteristics are studied by photoluminescence (PL), current–voltage (I-V) and capacitance - voltage (C-V) measurements. PL spectra indicated higher ultraviolet (UV) to visible emission ratio with a strong peak of near band edge emission (NBE) centered from 375-380 nm and very weak broad deep-level emissions (DLE) centered from 510-580 nm. All diodes show typical non linear rectifying behavior as characterized by I-V measurements. The results indicated that annealing in air and oxygen resulted in better electrical characteristics with a decrease in the reverse current.

scholarly journals Dependence of aging on inhomogeneities in InGaN/AlGaN/GaN light-emitting diodes

2000 ◽  
Vol 5 (S1) ◽  
pp. 668-674
Author(s):  
V.E. Kudryashov ◽  
S.S. Mamakin ◽  
A.N. Turkin ◽  
A.E. Yunovich ◽  
A.N. Kovalev ◽  
...  
Keyword(s):  
Space Charge ◽  
Quantum Efficiency ◽  
Space Charge Region ◽  
Radiation Intensity ◽  
Light Emitting Diodes ◽  
Reverse Current ◽  
Spectral Parameters ◽  
Light Emitting ◽  
Potential Fluctuations ◽  
Normal Currents

Changes of properties of green LEDs based on InxGa1−xN/AlyGa1−y/GaN heterostructures were studied during 150÷200 hours at currents J = 30÷ 80 MA The radiation intensity at low currents (0.1÷1 mA) is quite sensitive to such an aging, it falls down 10÷100 times. Quantum efficiency and spectral parameters at normal currents (J ≈ 10 mA) change non-monotonically during aging, some degradation is observed after 168 hours. The degradation is observed also after a short (< 1 min) period of reverse current. These phenomena are discussed in terms of under threshold defect’s formation and their migration in the space charge region of p-n-heterojunction. Potential fluctuations in the space charge region are quite sensitive to this process.

Solar Cells prepared with Spray-ILGAR Indium Sulfide buffer layers on Cu(In,Ga)Se2 Absorbers

2005 ◽  
Vol 865 ◽  
Author(s):  
Nicholas A. Allsop ◽  
Christian A. Kaufmann ◽  
Axel Neisser ◽  
Marin Rusu ◽  
Andreas Hänsel ◽  
...  
Keyword(s):  
Activation Energy ◽  
Solar Cells ◽  
Space Charge ◽  
Cadmium Sulfide ◽  
Space Charge Region ◽  
Buffer Layers ◽  
Indium Sulfide ◽  
Recombination Mechanism ◽  
Current Voltage ◽  
First Results

AbstractIndium sulfide buffer layers deposited by the Spray-Ion Layer Gas Reaction (Spray-ILGAR) technique have recently been used with Cu(In,Ga)(S,Se)2 absorbers giving cells with an efficiency equal to the cadmium sulfide references. In this paper we show the first results from cells prepared with Cu(In,Ga)Se2 absorbers (sulfur free). These cells reach an efficiency of 13.1% which remains slightly below the efficiency of the cadmium sulfide reference. However, temperature dependant current-voltage measurements reveal that the activation energy of the dominant recombination mechanism remains unchanged from the cadmium sulfide buffered cells indicating that recombination remains within the space charge region.

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