Irregular Electron Transport Through a-Si:H Based Potential Barriers

1993 ◽  
Vol 297 ◽  
Author(s):  
Norbert Bernhard ◽  
B. Frank ◽  
B. Movaghar ◽  
G.H. Bauer

Irregularities in the current-voltage-characteristics of a-Si:H based potential barriers have been investigated experimentally, and are discussed theoretically with respect to different transport mechanisms. The investigated samples were different series of double and single barrier a-Si:H - a-Si1-xCx:H - heterostructures, as well as homogeneous samples without heterostructure barrier. Current-voltage-(I-V)-characteristics showing a wide variety of features, from complete smoothness of the curves, to bumps and even accidental step-like switching behaviour, as well as different forms of noise, were recorded at different temperatures. Resonant tunnelling as an explaining transport mechanism for the anomalies was excluded because of inconsistency between experiment and calculations partially including special amorphous features. Instead it is argued that all observed irregularities, i. e. bumps in I-V-curves, switching-like behaviour, and appearance of noise, are related to current transport via trap-assisted tunnelling through locally strongly confined transport paths, leading to the meta-stable formation, change and break-down of conductory filaments.

1991 ◽  
Vol 05 (29) ◽  
pp. 1933-1938 ◽  
Author(s):  
M.H. CHOHAN ◽  
A.H. KHALID ◽  
M. ZULFIQAR ◽  
P.K. BUTT ◽  
FARAH KHAN ◽  
...  

Electron transport mechanisms in cobalt polymethacrylate have been investigated. The electrical measurements made on the polymer, show that the current-voltage relationship at lower voltages (V<300 V) is ohmic whereas at higher voltages it is exponential. The strong temperature dependence of current on voltage indicates the dominance of a Poole-Frenkel mechanism and the existence of trapping levels. Low activation energy values suggest an electronic conduction mechanism.


2021 ◽  
Vol 91 (11) ◽  
pp. 1769
Author(s):  
М.В. Кузьмин ◽  
М.А. Митцев

Using the energy diagrams of asymmetric potential barriers formed at the contact of two metals with different work functions, the influence of contact potential difference on the current-voltage characteristics and differential conductivity spectra measured by scanning tunneling spectroscopy is considered. It is shown that the obtained conclusions are in qualitative agreement with the experimental results for ytterbium nanofilms with the thickness of 16 monolayers (6.08 nm). However, they significantly differ quantitatively. The analysis of such diffrences is performed.


Author(s):  
I.A. Tarasov ◽  
M.V. Rautskii ◽  
I.A. Yakovlev ◽  
M.N. Volochaev

AbstractSelf-assembled growth of α-FeSi_2 nanocrystal ensembles on gold-activated and gold-free Si(001) surface by molecular beam epitaxy is reported. The microstructure and basic orientation relationship (OR) between the silicide nanocrystals and silicon substrate were analysed. The study reveals that utilisation of the gold as catalyst regulates the preferable OR of the nanocrystals with silicon and their habitus. It is shown that electron transport from α-FeSi2 phase into p-Si(001) can be tuned by the formation of (001)—or (111)—textured α-FeSi2 nanocrystals ensembles. A current-voltage characteristic of the structures with different preferable epitaxial alignment (α-FeSi_2(001)/Si(100) and α-FeSi_2(111)/Si(100)) shows good linearity at room temperature. However, it becomes non-linear at different temperatures for different ORs due to different Schottky barrier height governed by a particular epitaxial alignment of the α-FeSi_2/ p -Si interfaces.


2018 ◽  
Vol 284 ◽  
pp. 182-187
Author(s):  
E.E. Blokhin ◽  
D.A. Arustamyan ◽  
L.M. Goncharova

In this paper we present the results of investigation of heterostructures with an array of InAs quantum dots grown on GaAs substrates with GaAs and AlGaAs front barriers for high-speed near-IR photodetectors. The thickness of the barrier layers did not exceed 30 nm. It is shown that the ion-beam deposition method makes it possible to grow quantum dots with lateral dimensions up to 30 nm and 15 nm height. The spectral dependences of the external quantum efficiency and dark current-voltage characteristics are investigated.


2015 ◽  
Vol 6 ◽  
pp. 2431-2437 ◽  
Author(s):  
Yuki Komoto ◽  
Shintaro Fujii ◽  
Tomoaki Nishino ◽  
Manabu Kiguchi

We report on an experimental analysis of the charge transport properties of single mesitylene (1,3,5-trimethylbenzene) molecular junctions. The electronic conductance and the current–voltage characteristics of mesitylene molecules wired into Au electrodes were measured by a scanning tunnelling microscopy-based break-junction method at room temperature in a liquid environment. We found the molecular junctions exhibited two distinct conductance states with high conductance values of ca. 10−1 G 0 and of more than 10−3 G 0 (G 0 = 2e 2/h) in the electronic conductance measurements. We further performed a statistical analysis of the current–voltage characteristics of the molecular junctions in the two states. Within a single channel resonant tunnelling model, we obtained electronic couplings in the molecular junctions by fitting the current–voltage characteristics to the single channel model. The origin of the high conductance was attributed to experimentally obtained large electronic couplings of the direct π-bonded molecular junctions (ca. 0.15 eV). Based on analysis of the stretch length of the molecular junctions and the large electronic couplings obtained from the I–V analysis, we proposed two structural models, in which (i) mesitylene binds to the Au electrode perpendicular to the charge transport direction and (ii) mesitylene has tilted from the perpendicular orientation.


2014 ◽  
Vol 778-780 ◽  
pp. 657-660 ◽  
Author(s):  
Ulrike Grossner ◽  
Francesco Moscatelli ◽  
Roberta Nipoti

Two families of Al+implanted vertical p+in diodes that have been processed all by identical steps except the post implantation annealing one have been characterized with current voltage measurements from -100 to +5V at different temperatures. Analysis of the static forward current voltage characteristics shows two different ideality factor regions, which are distinct for each family. The reverse current voltage characteristics reveals corresponding two different activation energies. These are assumed to be correlated to the Z1/2defect for the one case and another one with an activation energy of 0.25eV.


Author(s):  
А.А. Ширяев ◽  
В.М. Воротынцев ◽  
Е.Л. Шоболов

The opportunity to predict trapped charge value in buried silicon oxide of silicon-on-insulator structures using Poole−Frenkel effect was investigated. Using measuring and modeling of current–voltage characteristics of buried silicon oxide at different temperatures conditions for Poole−Frenkel effect in this layer were determined. Processes taking place in buried oxide during measurement of current–voltage characteristics and annealing were considered. Conditions of thermal field treatment of buried oxide for radiation exposure imitation using injection were determined. Dependence of accumulated positive charge value in buried silicon oxide as a result of injection on Poole−Frenkel current value was estimated. The opportunity to use Poole−Frenkel effect for buried oxide defectiveness evaluation during manufacturing of microcircuits with enhanced dose radiation hardness is shown.


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