scholarly journals On the Examination of Temperature-Dependent Possible Current-Conduction Mechanisms of Au/(nanocarbon-PVP)/n-Si Schottky Barrier Diodes in Wide Range of Voltage

2021 ◽  
Author(s):  
Ömer SEVGİLİ
Keyword(s):  
Barrier Height ◽  
Linear Part ◽  
Forward Bias ◽  
Surface States ◽  
Image Force ◽  
Positive Temperature ◽  
Zero Bias ◽  
Conduction Mechanisms ◽  
Wide Range ◽  
Current Conduction

Abstract Au/(nanocarbon-PVP)/n-Si SDs were fabricated and their current-conduction mechanisms (CCMs) have been examined in elaborative by utilizing current-voltage (I-V) characteristics in temperature range of 60-340K at (± 3V) ranges. The values of ideality factor (n) and zero-bias barrier height (ΦBo) determined from the linear-part of semilogarithmic forward bias IF-VF properties based on Thermionic-Emission (TE) theory revealed that decrease in ΦBo and increase in n with deccreasing temperature. Additionally, Richardson constant (A*) value was found several orders lower than its theoretical value. The values of ΦBo and n changed from 0.173 eV to 0.837 eV and 6.60 to 2.85 with increasing temperature from 60 K to 340 K. This positive temperature-coefficient (α) of ΦBo is inagreement with the bandgap of semiconductor or barrier height (BH) for the ideal diode. The calculated higher value of n at low temperatures was attributed to the inhomogeneities of BH rather than the interlayer, surface-states (Nss), and image-force lowering. With lowing temperatures, CCMs may be governed by tunneling over the lower barriers, via Nss, and generation recombination (GR), as well as TE and hence a complete description of CCM and understanding of the formation BH, remain a compelling problem. Nss-(Ec-Ess) profile was also obtained from IF-VF data for each temperature.

Current-transport mechanism in Au/V-doped PVC+TCNQ/p-Si structures

2015 ◽  
Vol 29 (13) ◽  
pp. 1550076 ◽  
Author(s):  
H. Tecimer ◽  
Ö. Vural ◽  
A. Kaya ◽  
Ş. Altındal
Keyword(s):  
Temperature Coefficient ◽  
Transport Mechanism ◽  
Forward Bias ◽  
Thermionic Emission ◽  
Negative Temperature ◽  
Positive Temperature ◽  
Current Transport ◽  
Insulator Layer ◽  
Zero Bias ◽  
Current Transport Mechanism

The forward and reverse bias current–voltage (I–V) characteristics of Au/V-doped polyvinyl chloride+Tetracyanoquino dimethane/porous silicon (PVC+TCNQ/p-Si) structures have been investigated in the temperature range of 160–340 K. The zero bias or apparent barrier height (BH) (Φ ap = Φ Bo ) and ideality factor (n ap = n) were found strongly temperature dependent and the value of n ap decreases, while the Φ ap increases with the increasing temperature. Also, the Φ ap versus T plot shows almost a straight line which has positive temperature coefficient and it is not in agreement with the negative temperature coefficient of ideal diode or forbidden bandgap of Si (α Si = -4.73×10-4 eV/K ). The high value of n cannot be explained only with respect to interfacial insulator layer and interface traps. In order to explain such behavior of Φ ap and n ap with temperature, Φ ap Versus q/2kT plot was drawn and the mean value of (Φ Bo ) and standard deviation (σs) values found from the slope and intercept of this plot as 1.176 eV and 0.152 V, respectively. Thus, the modified ( ln (Io/T2)-(qσs)2/2(kT)2 versus (q/kT) plot gives the Φ Bo and effective Richardson constant A* as 1.115 eV and 31.94 A ⋅(cm⋅K)-2, respectively. This value of A*( = 31.94 A⋅( cm ⋅K)-2) is very close to the theoretical value of 32 A ⋅(cm⋅K)-2 for p-Si. Therefore, the forward bias I–V–T characteristics confirmed that the current-transport mechanism (CTM) in Au/V-doped PVC+TCNQ/p-Si structures can be successfully explained in terms of the thermionic emission (TE) mechanism with a Gaussian distribution (GD) of BHs at around mean BH.

Current conduction mechanisms in thermal nitride and dry gate oxide grown on 4H-silicon carbide (SiC)

2017 ◽  
Vol 20 (1) ◽  
Author(s):  
Li Liu ◽  
Yin-Tang Yang
Keyword(s):  
Barrier Height ◽  
Conduction Mechanism ◽  
Gate Oxide ◽  
Annealed Sample ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Mos Capacitors ◽  
Electrical Fields ◽  
Conduction Mechanisms ◽  
Current Conduction

AbstractCurrent conduction mechanisms of SiC metal-oxide-semiconductor (MOS) capacitors on n-type 4H-SiC with or without NO annealing have been investigated in this work. It has been revealed that Fowler-Nordheim (FN) tunneling is the dominating current conduction mechanism in high electrical fields, with barrier height of 2.67 and 2.54 eV respectively for samples with NO and without NO annealing. A higher barrier height for NO-annealed sample indicates the effect of N element on the SiC/SiO

ELECTRICAL PROPERTIES OF Al/p-Si STRUCTURE WITH Al2O3 THIN FILM FABRICATED BY ATOMIC LAYER DEPOSITION SYSTEM

2016 ◽  
Vol 24 (06) ◽  
pp. 1750077
Author(s):  
DILBER ESRA YİLDİZ ◽  
HATICE KANBUR CAVUŞ
Keyword(s):  
Atomic Layer Deposition ◽  
Barrier Height ◽  
Image Force ◽  
Atomic Layer ◽  
State Density ◽  
Mis Structure ◽  
Insulator Layer ◽  
Zero Bias ◽  
Energy Density Distribution ◽  
Layer Deposition

Al2O3 insulator layer was deposited by atomic layer deposition (ALD) technique on p-type Si [Formula: see text] and the Al/Al2O3/p-Si metal/insulator/semiconductor (MIS) structures were fabricated. The current–voltage ([Formula: see text]) characteristics of these structures were investigated in two different temperatures. The main electrical parameters such as the ideality factor ([Formula: see text]), zero bias barrier height ([Formula: see text]), and series resistance ([Formula: see text]) values were found for 300 and 400[Formula: see text]K. The energy density distribution profiles of the interface state density ([Formula: see text]) were determined from the [Formula: see text] characteristics. In addition, the capacitance–voltage ([Formula: see text]) and conductance–voltage ([Formula: see text]) characteristics of devices were investigated in the frequency range 50–1000[Formula: see text]kHz at room temperature. Frequency-dependent electrical characteristics such as doping acceptor concentration ([Formula: see text]), energy difference between the valance band edge and bulk Fermi level ([Formula: see text]), diffusion potential ([Formula: see text]), barrier height ([Formula: see text]), the image force barrier lowering ([Formula: see text]), maximum electric field ([Formula: see text]), and [Formula: see text] values were determined using [Formula: see text] and [Formula: see text] plots. In addition, the [Formula: see text] values were performed using Hill–Coleman method. According to experimental results, the locations of [Formula: see text] and [Formula: see text] have an important effect on [Formula: see text], [Formula: see text] and [Formula: see text] plots of MIS structure.

A comparative study on the electrical parameters of Au/n-Si Schottky diodes with and without interfacial (Ca1.9Pr0.1Co4Ox) layer

2016 ◽  
Vol 30 (16) ◽  
pp. 1650090 ◽  
Author(s):  
A. Kaya ◽  
H. G. Çetinkaya ◽  
Ş. Altındal ◽  
İ. Uslu
Keyword(s):  
Barrier Height ◽  
Room Temperature ◽  
Voltage Dependence ◽  
Schottky Diodes ◽  
Forward Bias ◽  
Surface States ◽  
Electrical Parameters ◽  
Distribution Profile ◽  
Text Data ◽  
Energy Density Distribution

In order to compare the main electrical parameters such as ideality factor [Formula: see text], barrier height (BH) [Formula: see text], series [Formula: see text] and shunt [Formula: see text] resistances and energy density distribution profile of surface states [Formula: see text], the [Formula: see text]-[Formula: see text] (MS) Schotthy diodes (SDs), with and without interfacial [Formula: see text] layer were obtained from the current–voltage [Formula: see text]–[Formula: see text] measurements at room temperature. The other few electrical parameters such as Fermi energy level [Formula: see text], BH [Formula: see text]), [Formula: see text] and voltage dependence of [Formula: see text] profile were also obtained from the capacitance–voltage [Formula: see text]–[Formula: see text] measurements. The voltage dependence of [Formula: see text] profile has two distinctive peaks in the depletion region for two diodes and they were attributed to a particular distribution of [Formula: see text] located at metal–semiconductor (MS) interface. All of these results have been investigated at room temperature and results have been compared with each other. Experimental results confirmed that interfacial [Formula: see text] layer enhanced diode performance in terms of rectifier rate [Formula: see text] at [Formula: see text], [Formula: see text] [Formula: see text]at [Formula: see text] and [Formula: see text] [Formula: see text] with values of 265, [Formula: see text] and [Formula: see text] for MS type Schottky barrier diode and [Formula: see text], [Formula: see text] and [Formula: see text] for metal–insulator–semiconductor (MIS) type SBD, respectively. It is clear that the rectifying ratio of MIS type SBD is about 9660 times greater than MS type SBD. The value of barrier height (BH) obtained from [Formula: see text]–[Formula: see text] data is higher than the forward bias [Formula: see text]–[Formula: see text] data and it was attributed to the nature of measurements. These results confirmed that the interfacial [Formula: see text] layer has considerably improved the performance of SD.

scholarly journals Electrical and Photoelectric Properties of Heterojunctions MoOx/n-Cd1-xZnxTe

2021 ◽  
Keyword(s):  
Temperature Coefficient ◽  
Barrier Height ◽  
Potential Barrier ◽  
Reverse Bias ◽  
Short Circuit ◽  
Forward Bias ◽  
Surface States ◽  
Potential Barrier Height ◽  
Polished Surface ◽  
Photoelectric Properties

The paper presents the results of studies of the optical and electrical properties of МоOx/n-Cd1-хZnхTe semiconductor heterojunctions made by depositing MoOx films on a pre-polished surface of n-Cd1-хZnхTe plates (5 × 5 × 0.7 mm3) in a universal vacuum installation Leybold - Heraeus L560 using reactive magnetron sputtering of a pure Mo target. Such studies are of great importance for the further development of highly efficient devices based on heterojunctions for electronics and optoelectronics. The fabricated МоOx/n‑Cd1‑хZnхTe heterojunctions have a large potential barrier height at room temperature (φ0 = 1.15 eV), which significantly exceeds the analogous parameter for the МоOx/n-CdTe heterojunction (φ0 = 0.85 eV). The temperature coefficient of the change in the height of the potential barrier was experimentally determined to be d(φ0)/dT = -8.7·10-3 eV K, this parameter is four times greater than the temperature coefficient of change in the height of the potential barrier for MoOx/n-CdTe heterostructures. The greater value of the potential barrier height of the МоOx/n-Cd1-хZnхTe heterojunction is due to the formation of an electric dipole at the heterointerface due to an increase in the concentration of surface states in comparison with MoOx/n-CdTe heterostructures, and this is obviously associated with the presence of zinc atoms in the space charge region and at the metallurgical boundary section of the heteroboundary. In МоOx/n‑Cd1-хZnхTe heterojunctions, the dominant mechanisms of current transfer are generation-recombination and tunneling-recombination with the participation of surface states, tunneling with forward bias, and tunneling with reverse bias. It was found that МоOx/n-Cd1-хZnхTe heterojunctions, which have the following photoelectric parameters: open circuit voltage Voc = 0.3 V, short circuit current Isc = 1.2 mA/cm2, and fill factor FF = 0.33 at an illumination intensity of 80 mW/cm2 are promising for the manufacture of detectors of various types of radiation. The measured and investigated impedance of the МоOx/n-Cd1-хZnхTe heterojunction at various reverse biases, which made it possible to determine the distribution of the density of surface states and the characteristic time of their charge-exchange, which decrease with increasing reverse bias.

Magnetic Quantum Oscillations from Surface States of Bi Nanowires

2011 ◽  
Vol 1350 ◽  
Author(s):  
L. A. Konopko ◽  
T. E. Huber ◽  
A. A. Nikolaeva
Keyword(s):  
Single Crystal ◽  
Low Temperatures ◽  
Surface States ◽  
Charge Carriers ◽  
Quantum Oscillations ◽  
Wide Range ◽  
Spin Orbit Interactions ◽  
Conducting Tube ◽  
Magnetic Quantum Oscillations ◽  
Strong Spin

ABSTRACTIn this work, we report the results of studies of the transverse magnetoresistance (MR) of single-crystal Bi nanowires with diameter d<80 nm. The single-crystal nanowire samples were prepared by the Taylor-Ulitovsky technique. Due to the semimetal-to-semiconductor transformation and high density of surface states with strong spin-orbit interactions, the charge carriers are confined to the conducting tube made of surface states. The non monotonic changes of transverse MR that are equidistant in a direct magnetic field were observed at low temperatures in a wide range of magnetic fields up to 14 T. The period of oscillations depends on the wire diameter d as for the case of longitudinal MR. An interpretation of transverse MR oscillations is presented.

The Effect of Surface States on Secondary Electron (SE) Dopant Contrast from Silicon p-n Junctions

2007 ◽  
Vol 1026 ◽  
Author(s):  
Augustus K. W. Chee ◽  
Conny Rodenburg ◽  
Colin John Humphreys
Keyword(s):  
Oxide Layer ◽  
Computer Modelling ◽  
Surface States ◽  
Native Oxide ◽  
Native Oxide Layer ◽  
Element Analysis ◽  
Surface Band ◽  
Band Bending ◽  
Wide Range ◽  
Se Doping

AbstractDetailed computer modelling using finite-element analysis was performed for Si p-n junctions to investigate the effects of surface states and doping concentrations on surface band-bending, surface junction potentials and external patch fields. The density of surface states was determined for our Si specimens with a native oxide layer. Our calculations show that for a typical density of surface states for a Si specimen with a native oxide layer, the effects of external patch fields are negligible and the SE doping contrast is due to the built-in voltage across the p-n junction modified by surface band-bending. There is a good agreement between the experimental doping contrast and the calculated junction potential just below the surface, taking into account surface states, for a wide range of doping concentrations.

Metal Contacts on a-GaN

1996 ◽  
Vol 1 ◽  
Author(s):  
T. U. Kampen ◽  
W. Mönch
Keyword(s):  
Tight Binding ◽  
Image Force ◽  
Schottky Contacts ◽  
Metal Contacts ◽  
Zero Bias ◽  
Barrier Heights ◽  
Current Voltage ◽  
Optical Dielectric Constant ◽  
Optical Dielectric ◽  
Gap States

The Schottky barrier heights of silver and lead contacts on n-type GaN (0001) epilayers were determined from current-voltage characteristics. The zero-bias barrier heights and the ideality factors were found to be linearly correlated. Similar observations were previously reported for metal contacts on Si (111) and GaAs (110) surfaces. The barrier heights of ideal Schottky contacts are characterized by image force lowering of the barrier only. This gives an ideality factor of 1.01. From our data we obtain barrier heights of 0.82 eV and 0.73eV for ideal Ag and Pb contacts on GaN, respectively. The metal-induced gap states (MIGS) model predicts the barrier heights of ideal Schottky contacts on a given semiconductor to be linearly correlated with the electronegativities of the metals. The two important parameters of this MIGS-and-electronegativity model are the charge neutrality level (CNL) of the MIGS and a slope parameter. The CNL may be calculated from the dielectric band gap and using the empirical tight-binding method. The slope parameters are given by the optical dielectric constant of the respective semiconductor. The predictions of the MIGS model for metal/GaN contacts are confirmed by the results presented here and by barrier heights previously reported by others for Au, Ti, Pt, and Pd contacts on GaN.

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