Majority Carrier Transport Across Semiconductor Grain Boundaries

1990 ◽  
Vol 209 ◽  
Author(s):  
S.F. Nelson ◽  
P.V. Evans ◽  
S.L. Sass ◽  
D.A. Smith
Keyword(s):  
Carrier Transport ◽  
High Vacuum ◽  
Thermionic Emission ◽  
Ultra High Vacuum ◽  
Defect States ◽  
Intrinsic Structure ◽  
Majority Carrier ◽  
Float Zone ◽  
Current Voltage ◽  
Misorientation Angles

AbstractMajority carrier transport measurements were made across the potential barriers at (100) twist boundaries in silicon. The bicrystals were prepared by hot-pressing single crystals of lightly doped float-zone material, under ultra-high vacuum conditions. The current - voltage measurements were analyzed using combined drift-diffusion and thermionic emission transport mechanisms, and incorporating some inhomogeneity in the charge distribution at the boundary. Evidence has been found for a small, Nd = 3 × 1010 cm−2, density of mono-energetic defect states near midgap, in bicrystals characterized by a variety of misorientation angles. This density is too small to result from the intrinsic structure of the boundary. In addition, no dependence was found on misorientation angle.

Electrical Study of Schottky Barriers on Cleaved InP and GaAs (110) Surfaces

1985 ◽  
Vol 54 ◽  
Author(s):  
N. Newman ◽  
M. van Schilfgaarde ◽  
T. Kendelewicz ◽  
W. E. Spicer
Keyword(s):  
Barrier Height ◽  
Ideality Factor ◽  
High Vacuum ◽  
Forward Bias ◽  
Thermionic Emission ◽  
Ultra High Vacuum ◽  
Leakage Currents ◽  
Current Voltage ◽  
Measuring Techniques

We have performed a systematic study of the electrical properties of a large number of metal/n-GaAs and metal/n-InP diodes. Diodes were fabricated on clean cleaved InP and GaAs (110) surfaces in ultra-high vacuum with in-situ metal deposition of Cr, Mn, Sn, Ni, Al, Pd, Cu, Ag and Au. Using current-voltage (I-V) and capacitance-voltage (C-V) measuring techniques, we were able to obtain very reliable and consistent determinations of the barrier height, θ/b, and ideality factor, n. All of the metal-semiconductor systems formed on lightly doped (< 5×1016/cm3) substrates were characterized by near-unity (1.05) ideality factors.The effects of doping on the electrical characteristics of the n-GaAs diodes were investigated. A decrease in the effective I-V barrier height, an increase in the ideality factor in forward bias and a strong voltage dependence on the thermionic emission currents in reverse bias were found for diodes formed on the more heavily doped samples. These changes are essentially metal-independent, but depend strongly on the doping of the substrate. The characterization (and elimination in some cases) of peripheral leakage currents from the thermionic emission current for the n-GaAs systems was found to be essential in obtaining consistent results in our work and in reinterpreting some of the prior work in the literature. The dominant leakage current in the GaAs diodes flows through a small area, low barrier at the periphery of the device and can be eliminated by mesa etching.

Investigation of carrier transport mechanisms in the Cu–Zn–Se based hetero-structure grown by sputtering technique

2018 ◽  
Vol 96 (7) ◽  
pp. 816-825 ◽  
Author(s):  
H.H. Güllü ◽  
M. Terlemezoğlu ◽  
Ö. Bayraklı ◽  
D.E. Yıldız ◽  
M. Parlak
Keyword(s):  
Barrier Height ◽  
Carrier Transport ◽  
Thermionic Emission ◽  
Electrical Characterization ◽  
Band Gap Energy ◽  
Zero Bias ◽  
Hetero Structure ◽  
Current Voltage ◽  
P Type

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.

Electronics Application for Fullerenes

1994 ◽  
Vol 349 ◽  
Author(s):  
R.L. McNally ◽  
F R. Brotzen ◽  
A.J. Griffin ◽  
P.J. Loos ◽  
E.V. Barrera
Keyword(s):  
Thin Film ◽  
Applied Voltage ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Concentration Profiles ◽  
Wavelength Dispersive Spectroscopy ◽  
Sem Micrographs ◽  
Noticeable Change ◽  
Metal Semiconductor Metal ◽  
Current Voltage

ABSTRACTThin-film Al-C60-Al trilayered structures were sublimated under ultra high vacuum (UHV) conditions for the purpose of investigating their current-voltage (I-V) properties. These metal-semiconductor-metal devices exhibited rapid and irreversible drop in resistance of about two orders of magnitude under an applied voltage of 0.67 to 0.75V. Approximate initial and final resistances were 1050 Ω and 8 Ω respectively. Wavelength Dispersive Spectroscopy (WDS) indicated no noticeable change in phase of the fullerene inter-layer after the irreversible drop in resistance. These results, SEM micrographs and concentration profiles were concordant with diffusion of top layer Al through the fullerene layer as the most likely cause of the change in resistance.

scholarly journals Field Emission Properties of Polymer Graphite Tips Prepared by Membrane Electrochemical Etching

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1294
Author(s):  
Alexandr Knápek ◽  
Rashid Dallaev ◽  
Daniel Burda ◽  
Dinara Sobola ◽  
Mohammad M. Allaham ◽  
...  
Keyword(s):  
Field Emission ◽  
Electrochemical Etching ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Test Field ◽  
Current Voltage ◽  
Field Emission Microscopy ◽  
Emission Behavior ◽  
Current Voltage Characteristics ◽  
Emission Microscopy

This paper investigates field emission behavior from the surface of a tip that was prepared from polymer graphite nanocomposites subjected to electrochemical etching. The essence of the tip preparation is to create a membrane of etchant over an electrode metal ring. The graphite rod acts here as an anode and immerses into the membrane filled with alkali etchant. After the etching process, the tip is cleaned and analyzed by Raman spectroscopy, investigating the chemical composition of the tip. The topography information is obtained using the Scanning Electron Microscopy and by Field Emission Microscopy. The evaluation and characterization of field emission behavior is performed at ultra-high vacuum conditions using the Field Emission Microscopy where both the field electron emission pattern projected on the screen and current–voltage characteristics are recorded. The latter is an essential tool that is used both for the imaging of the tip surfaces by electrons that are emitted toward the screen, as well as a tool for measuring current–voltage characteristics that are the input to test field emission orthodoxy.

Characterization of Zirconium - Diamond Interfaces

1996 ◽  
Vol 423 ◽  
Author(s):  
P. K. Baumann ◽  
S. P. Bozeman ◽  
B. L. Ward ◽  
R. J. Nemanich
Keyword(s):  
Electron Affinity ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Threshold Field ◽  
Diamond Surfaces ◽  
Field Emission Current ◽  
Current Voltage ◽  
Single Crystal Diamond ◽  
A Current

AbstractThin Zr films were deposited on natural single crystal diamond (100) substrates by ebeam evaporation in ultra-high vacuum (UHV). Before metal deposition the surfaces were cleaned by UHV anneals at either 500°C or 1150°C. Following either one of these treatments a positive electron affinity was determined by means of UV photoemission spectroscopy (UPS). Depositing 2Å of Zr induced a NEA on both surfaces. Field emission current - voltage measurements resulted in a threshold field (for a current of 0.1 µA) of 79 V/µm for positive electron affinity diamond surfaces and values as low as 20 V/µm for Zr on diamond.

Nanowire Reconstruction on the 4H-SiC(1102) Surface

2007 ◽  
Vol 556-557 ◽  
pp. 529-532 ◽  
Author(s):  
M. Hetzel ◽  
Charíya Virojanadara ◽  
Wolfgang J. Choyke ◽  
Ulrich Starke
Keyword(s):  
Electron Spectroscopy ◽  
Auger Electron ◽  
Surface Composition ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Intrinsic Structure ◽  
Low Energy Electron Diffraction ◽  
Low Energy Electron

Ordered reconstruction phases on the 4H-SiC(1102) surface have been investigated using low-energy electron diffraction (LEED), Auger electron spectroscopy (AES) and scanning tunneling microscopy (STM). After initial hydrogen etching, the samples were prepared by Si deposition and annealing in ultra-high vacuum (UHV). Two distinct reconstruction phases develop upon annealing, first with a (2×1), and at higher temperatures with a c(2×2) LEED pattern. After further annealing the fractional order LEED spots vanish and a (1x1) pattern develops. For the (2×1) phase, STM micrographs show that adatom chains develop on large flat terraces, which in view of AES consist of additional Si. These highly linear and equidistant chains represent a self-assembled well-ordered pattern of nanowires developing due to the intrinsic structure of the 4H-SiC(1102) surface. For the c(2×2) phase AES indicates a surface composition close to the bulk stoichiometry. For the (1×1) phase a further Si depletion is observed.

INVESTIGATION ON DEVICE CHARACTERISTICS OF n-CdS/p-Ag(Ga-In)Te2 HETEROJUNCTION DIODE

2018 ◽  
Vol 25 (05) ◽  
pp. 1850107 ◽  
Author(s):  
Ö. BAYRAKLI ◽  
H. H. GÜLLÜ ◽  
M. PARLAK
Keyword(s):  
Carrier Transport ◽  
Thermionic Emission ◽  
Sample Temperature ◽  
Glass Substrates ◽  
Parasitic Resistance ◽  
Current Voltage ◽  
Different Temperatures ◽  
Evaporation Technique ◽  
Device Properties ◽  
Good Agreement

This work indicates the device properties of polycrystalline p-AgGaInTe2 (AGIT) thin films deposited on bare and ITO-coated glass substrates with thermal evaporation technique. Device characteristics of n-CdS/p-AGIT heterostructure have been analyzed in terms of current–voltage ([Formula: see text]–[Formula: see text]) for different temperatures and capacitance–voltage ([Formula: see text]–[Formula: see text]) measurements for different frequencies, respectively. The series and shunt resistances were determined from the analysis of parasitic resistance for high forward and reverse bias voltages, respectively. The ideality factors were evaluated from [Formula: see text]–[Formula: see text] variation at each sample temperature as lying in between 2.51 and 3.25. The barrier height was around 0.79[Formula: see text]eV at room temperature. For low bias region, the variation in the diode parameters due to the sample temperature exhibited the thermionic emission with [Formula: see text] anomaly, whereas space-charge-limited current analysis was also found to be pre-dominant carrier transport mechanism for this heterostructure. From [Formula: see text]–[Formula: see text] measurements, the obtained built-in potential and series resistances were found to be in good agreement with [Formula: see text]–[Formula: see text] results.

Mechanism of Carrier Transport in n-Type β-FeSi2/Intrinsic Si/p-Type Si Heterojunctions

2015 ◽  
Vol 1119 ◽  
pp. 189-193
Author(s):  
Nathaporn Promros ◽  
Motoki Takahara ◽  
Ryuji Baba ◽  
Tarek M. Mostafa ◽  
Mahmoud Shaban ◽  
...  
Keyword(s):  
Ideality Factor ◽  
Carrier Transport ◽  
Linear Part ◽  
Forward Bias ◽  
Thermionic Emission ◽  
Forward Bias Voltage ◽  
Space Charge Limit ◽  
Current Voltage ◽  
P Type ◽  
Direct Current Sputtering

Preparation of n-type β-FeSi2/intrinsic Si/p-type Si heterojunctions was accomplished by facing-target direct-current sputtering (FTDCS) and measuring their current-voltage characteristic curves at low temperatures ranging from 300 K down to 50 K. A mechanism of carrier transport in the fabricated heterojunctions was investigated based on thermionic emission theory. According to this theory, the ideality factor was calculated from the slope of the linear part of the forward lnJ-V plot. The ideality factor was 1.12 at 300 K and increased to 1.99 at 225 K. The estimated ideality factor implied that a recombination process was the predominant mechanism of carrier transport. When the temperatures decreased below 225 K, the ideality factor was estimated to be higher than two and parameter A was estimated to be constant. The obtained results implied that the mechanism of carrier transport was governed by a trap-assisted multi-step tunneling process. At high forward bias voltage, the predominant mechanism of carrier transport was changed into a space charge limit current process.

Current Transport Mechanism of n-Type Nanocrystalline FeSi2/Intrinsic Si/p-Type Si Heterojunctions Fabricated by Facing-Targets Direct-Current Sputtering

2013 ◽  
Vol 802 ◽  
pp. 199-203 ◽  
Author(s):  
Nathaporn Promros ◽  
Suguru Funasaki ◽  
Ryūhei Iwasaki ◽  
Tsuyoshi Yoshitake
Keyword(s):  
Ideality Factor ◽  
Low Temperatures ◽  
Transport Mechanism ◽  
Carrier Transport ◽  
Thermionic Emission ◽  
Current Transport ◽  
Current Transport Mechanism ◽  
Current Voltage ◽  
P Type ◽  
Direct Current Sputtering

n-Type nanocrystalline FeSi2/intrinsic Si/p-type Si heterojunctions were successfully fabricated by FTDCS and their forward current-voltage characteristics at low temperatures were analyzed on the basis of thermionic emission theory. The analysis of J-V characteristics exhibits an increase in the ideality factor and a decrease in the barrier height at low temperatures. The values of ideality factor were estimated to be 2.26 at 300 K and 9.29 at 77 K. The temperature dependent ideality factortogether with the constant value of parameter A indicated that a trap assisted multi-step tunneling process is the dominant carrier transport mechanism in this heterojunction. At high voltages, the current transport mechanism is dominated by SCLC process.

Temperature Dependent Current-Voltage Characteristics of n-Type Nanocrystalline-FeSi2/p-Type Si Heterojunctions Fabricated by Pulsed Laser Deposition

2013 ◽  
Vol 858 ◽  
pp. 171-176
Author(s):  
Nathaporn Promros ◽  
Ryūhei Iwasaki ◽  
Suguru Funasaki ◽  
Kyohei Yamashita ◽  
Chen Li ◽  
...  
Keyword(s):  
Barrier Height ◽  
Ideality Factor ◽  
Carrier Transport ◽  
Series Resistance ◽  
Thermionic Emission ◽  
Temperature Dependent ◽  
Zero Bias ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
P Type

n-Type NC-FeSi2/p-type Si heterojunctions were successfully fabricated by PLD, and their forward current-voltage characteristics were analyzed on the basis of thermionic emission theory (TE) in the temperature range from 300 down to 77 K. With a decrease in the temperature, the ideality factor was increased while the zero-bias barrier height was decreased. The calculated values of ideality factor and barrier height were 3.07 and 0.63 eV at 300 K and 10.75 and 0.23 eV at 77 K. The large value of ideality factor indicated that a tunneling process contributes to the carrier transport mechanisms in the NC-FeSi2 films. The series resistance, which was estimated by Cheungs method, was strongly dependent on temperature. At 300 K, the value of series resistance was 12.44 Ω and it was dramatically enhanced to be 1.71× 105 Ω at 77 K.

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