scholarly journals Electrical Properties of Silicon Nanowires Schottky Barriers Prepared by MACE at Different Etching Time

Author(s):  
Ahlem Rouis ◽  
Neila Hizem ◽  
Mohamed Hassen ◽  
Adel kalboussi

Abstract This article focused on the electrical characterization of silicon nanowires Schottky barriers following structural analysis of nanowires grown on p-type silicon by Metal (Ag) Assisted Chemical Etching (MACE) method distinguished by their different etching time (5min, 10min, 25min). The SiNWs are well aligned and distributed almost uniformly over the surface of a silicon wafer. In order to enable electrical measurement on the silicon nanowires device, Schottky barriers were performed by depositing Al on the vertically aligned SiNWs arrays. The electrical properties of the resulting Al/SiNWs diodes were characterized by current voltage (I-V) and capacity voltage (C-V) measurements. Unlike the conventional Schottky diode, symmetrical current-voltage (I-V) characteristics have been observed with a rectification ratio < 4. The metal-semiconductor-metal (M-S-M) model was used to analyze the (I-V) characteristics by including two Schottky barriers at the interface between metal and SiNWs. The electron transport behavior is explained by the thermionic field emission method (TFE) which added the effect of the tunneling current compared to the conventional thermionic emission theory. The capacitance-voltage C-V characteristics of SiNWs depend on the bias voltage showing that the samples have an obvious space charge region. Symmetric behavior also appears in the C –V curves that confirm the MSM model.

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 404 ◽  
Author(s):  
Mariem Naffeti ◽  
Pablo Aitor Postigo ◽  
Radhouane Chtourou ◽  
Mohamed Ali Zaïbi

In this work, vertically aligned silicon nanowires (SiNWs) with relatively high crystallinity have been fabricated through a facile, reliable, and cost-effective metal assisted chemical etching method. After introducing an itemized elucidation of the fabrication process, the effect of varying etching time on morphological, structural, optical, and electrical properties of SiNWs was analysed. The NWs length increased with increasing etching time, whereas the wires filling ratio decreased. The broadband photoluminescence (PL) emission was originated from self-generated silicon nanocrystallites (SiNCs) and their size were derived through an analytical model. FTIR spectroscopy confirms that the PL deterioration for extended time is owing to the restriction of excitation volume and therefore reduction of effective light-emitting crystallites. These SiNWs are very effective in reducing the reflectance to 9–15% in comparison with Si wafer. I–V characteristics revealed that the rectifying behaviour and the diode parameters calculated from conventional thermionic emission and Cheung’s model depend on the geometry of SiNWs. We deduce that judicious control of etching time or otherwise SiNWs’ length is the key to ensure better optical and electrical properties of SiNWs. Our findings demonstrate that shorter SiNWs are much more optically and electrically active which is auspicious for the use in optoelectronic devices and solar cells applications.


2007 ◽  
Vol 22 (3) ◽  
pp. 578-586 ◽  
Author(s):  
S. Ruffell ◽  
J.E. Bradby ◽  
J.S. Williams ◽  
O.L. Warren

An in situ electrical measurement technique for the investigation of nanoindentation using a Hysitron Triboindenter is described, together with details of experiments to address some technical issues associated with the technique. Pressure-induced phase transformations in silicon during indentation are of particular interest but are not fully understood. The current in situ electrical characterization method makes use of differences in electrical properties of the phase-transformed silicon to better understand the sequence of transformations that occur during loading and unloading. Here, electric current is measured through the sample/indenter tip during indentation, with a fixed or variable voltage applied to the sample. This method allows both current monitoring during indentation and the extraction of current-voltage (I-V) characteristics at various stages of loading. The work presented here focuses on experimental issues that must be understood for a full interpretation of results from nanoindentation experiments in silicon. The tip/sample contact and subsurface electrical resistivity changes dominate the resultant current measurement. Extracting the component of contact resistance provides an extremely sensitive method for measuring the electrical properties of the material immediately below the indenter tip, with initial results from indentation in silicon showing that this is a very sensitive probe of subsurface structural and electrical changes.


2018 ◽  
Vol 96 (7) ◽  
pp. 816-825 ◽  
Author(s):  
H.H. Güllü ◽  
M. Terlemezoğlu ◽  
Ö. Bayraklı ◽  
D.E. Yıldız ◽  
M. Parlak

In this paper, we present results of the electrical characterization of n-Si/p-Cu–Zn–Se hetero-structure. Sputtered film was found in Se-rich behavior with tetragonal polycrystalline nature along with (112) preferred orientation. The band gap energy for direct optical transitions was obtained as 2.65 eV. The results of the conductivity measurements indicated p-type behavior and carrier transport mechanism was modelled according to thermionic emission theory. Detailed electrical characterization of this structure was carried out with the help of temperature-dependent current–voltage measurements in the temperature range of 220–360 K, room temperature, and frequency-dependent capacitance–voltage and conductance-voltage measurements. The anomaly in current–voltage characteristics was related to barrier height inhomogeneity at the interface and modified by the assumption of Gaussian distribution of barrier height, in which mean barrier height and standard deviation at zero bias were found as 2.11 and 0.24 eV, respectively. Moreover, Richardson constant value was determined as 141.95 Acm−2K−2 by means of modified Richardson plot.


1996 ◽  
Vol 448 ◽  
Author(s):  
N. Marcano ◽  
A. Singh

AbstractIn/n-In0.46Ga0.54P Schottky diode was fabricated by thermal evaporation of In on chemically etched surface of In0.45Ga0.54P:Si epitaxial layer grown on highly doped n type GaAs. The In metal formed a high quality rectifying contact to In0.46Ga0.54P:Si with a rectification ratio of 500. The direct current-voltage/temperature (I-V/T) characteristics were non-ideal with the values of the ideality factor (n) between 1.26-1.78 for 400>T>260 K. The forward I-V data strongly indicated that the current was controlled by the generation-recombination (GR) and thermionic emission (TE) mechanisms for temperature in the range 260-400 K. From the temperature variation of the TE reverse saturation current, the values of (0.75±0.05)V and the (4.5±0.5)×10-5 Acm-2K-2 for the zero bias zero temperature barrier height (φoo) and modified effective Richardson constant were obtained. The 1 MHz capacitance-voltage (C-V) data for 260 K < T < 400 K was analyzed in terms of the C-2-V relation including the effect of interface layer to obtain more realistic values of the barrier height (φbo). The temperature dependence of φbo was described the relation φbo =(0.86±10.03) - (8.4±0.7)×l0-4T. The values of φoo, obtained by the I-V and C-V techniques agreed well.


2006 ◽  
Vol 518 ◽  
pp. 235-240 ◽  
Author(s):  
M. Žunić ◽  
Z. Branković ◽  
G. Branković ◽  
D. Poleti

The effect of Co, Cr and Nb on the electrical properties of the grain boundaries of SnO2-based varistors was investigated. The powders were prepared by the method of evaporation and decomposition of solutions and suspensions. Varistor samples were obtained by uniaxial pressing followed by sintering at 1300 °C for 1h. The electrical properties of the grain-boundary region, such as resistance (R) and capacitance (C), were determined using ac impedance spectroscopy in the 27-330 °C temperature interval. Activation energies for conduction (EA) were calculated from the Arrhenius equation. The non-linear coefficients (α) and the breakdown electric fields (Eb) of the samples were determined from the current-voltage characteristics. The potential barrier height (Φb) was calculated using the Schottky-type conducting model. After a comparison of the characteristic parameters for different varistor compositions it was found that the Cr/Nb ratio has a crucial influence on the grain-boundary properties in SnO2 varistors.


2016 ◽  
Vol 858 ◽  
pp. 1170-1173 ◽  
Author(s):  
Giuseppe Greco ◽  
Ferdinando Iucolano ◽  
Filippo Giannazzo ◽  
Salvatore di Franco ◽  
Domenico Corso ◽  
...  

In this paper, the electrical properties of different metal/p-GaN contacts (Ti/Al, TiN/Ti/Al and Ni/Au) have been investigated to get a deeper understanding of the behavior of p-GaN/AlGaN/GaN heterostructures for normally-off HEMTs. In particular, the study of the temperature dependent current-voltage characteristics allowed to identify the dominant carrier transport mechanism at the metal/p-GaN interface (Thermionic Field Emission). From the fit of the experimental current-voltage data it was possible to determine the Schottky barrier height values for the three systems, 2.08 eV (Ti/Al), 1.57 eV (TiN/Ti/Al) and 1.89 eV (Ni/Au). Hence, choosing the highest barrier height contact (Ti/Al) as gate electrode on a p-GaN/AlGaN/GaN heterostructure, optimized based on simulations, allowed to obtain devices with a normally-off behavior and a positive Vth of +1.3 V.


1996 ◽  
Vol 449 ◽  
Author(s):  
J. T. Trexler ◽  
S. J. Pearton ◽  
P. H. Holloway ◽  
M. G. Mier ◽  
K. R. Evans ◽  
...  

ABSTRACTReactions between electron beam evaporated thin films of Ni/Au, Pd/Au, and Cr/Au on p-GaN with a carrier concentration of 9.8 × 1016 cm−3 were investigated in terms of their structural and electronic properties both as-deposited and following heat treatments up to 600°C (furnace anneals) and 900°C (RTA) in a flowing N2 ambient. Auger electron spectroscopy (AES) depth profiles were used to study the interfacial reactions between the contact metals and the p-GaN. The electrical properties were studied using room temperature current-voltage (1-V) measurements and the predominant conduction mechanisms in each contact scheme were determined from temperature dependent I-V measurements. The metallization schemes consisted of a 500 Å interfacial layer of Ni, Pd, or Cr followed by a 1000 Å capping layer of Au. All schemes were shown to be rectifying as-deposited with increased ohmic character upon heat treatment. The Cr/Au contacts became ohmic upon heating to 900°C for 15 seconds while the other schemes remained rectifying with lower breakdown voltages following heat treatment. The specific contact resistance of the Cr/Au contact was measured to be 4.3×10−1 Ωcm2. Both Ni and Cr have been shown to react with the underlying GaN above 400 °C while no evidence of a Pd:GaN reaction was seen. Pd forms a solid solution with the Au capping layer while both Ni and Cr tend to diffuse through the capping layer to the surface. All contacts were shown to have a combination of thermionic emission and thermionic field emission as their dominant conduction mechanism, depending on the magnitude of the applied reverse bias.


2013 ◽  
Vol 833 ◽  
pp. 13-16
Author(s):  
X.A. Mei ◽  
Min Chen ◽  
J. Liu ◽  
R.F. Liu

The electrical properties of Ho2O3-bismuth titanate (Bi4-xHoxTi3O12) prepared by a conventional ceramic technique have been investigated. At applied d.c. field below 200V/mm, the current-voltage curve of Ho-doped sample exhibits a simple ohmic behavior. The impedance spectrum of Ho-doped sample indicates that consist of semiconducting grain and moderately insulating grain boundary regions. XRD, SEM and EPMA analyses reveal crystalline phase characterized by a Bi-layered perovskite structure of Bi4Ti3O12 and the distribution of every element is uniform. Ho-doped sample exhibit randomly oriented and plate-like morphology.


2015 ◽  
Vol 14 (03) ◽  
pp. 1550029 ◽  
Author(s):  
Alexey V. Klyuev ◽  
Arkady V. Yakimov ◽  
Irene S. Zhukova

We have studied the forward current–voltage (I–V) characteristics of Ti–Au /n-type GaAs Schottky barrier diodes. However, we found some anomalies in I–V characteristics. Hence, we have considered a model that incorporates thermionic emission, thermionic-field emission and leakage components. Leakage component is linear and visible at rather small currents. The anomalies observed in the diode parameters were effectively construed in terms of the contribution of these multiple charge transport mechanisms across the interface of the diodes. It is shown that thermionic-field emission and leakage are the sources of low-frequency (1/f) noise in such type of diodes. Various Schottky diode parameters were also extracted from the I–V characteristics and current dependence of spectrum of 1/f voltage noise.


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