Fabrication and Characterization of GaAs Tunnel Diode and ErAs Nanoparticles Enhanced GaAs Tunnel Diode for Multijunction Solar Cell

2014 ◽  
Vol 1602 ◽  
Author(s):  
Tomah Sogabe ◽  
Yasushi Shoji ◽  
Mitsuyoshi Ohba ◽  
Naito Shunya ◽  
Naoya Miyashita ◽  
...  
Keyword(s):  
Hysteresis Loop ◽  
Contact Area ◽  
Tunnel Diode ◽  
Enhancement Effect ◽  
Peak Current Density ◽  
Gaas Sample ◽  
Load Line ◽  
Current Voltage ◽  
Fabrication And Characterization

ABSTRACTWe report here the fabrication and characterization of GaAs tunnel diode (TD) and ErAs nanoparticles (Nps) enhanced GaAs TD. Four GaAs TDs with different contact area were fabricated by using MOCVD. We found extremely high peak current density of ∼250A/cm2 for the TD with r=0.25mm contact area. Moreover a hysteresis loop was appeared during sweeping up and sweeping down the external voltage. A ‘vector load line model’ was proposed to explain the origin of the shape of the hysteresis loop and the onset of the bistability occurred at the intersect of the loadline and the current-voltage (I-V) curve of TD. Meanwhile, we have grown ErAs Nps on GaAs(100) surface by using MBE and succeeded in overgrowth of GaAs after ErAs deposition. GaAs(p+)/ErAs(Nps)/GaAs(n+) TDs were fabricated and characterized. We found the GaAs sample containing 70s deposition of ErAs showed the best TD behavior. No TD behavior was observed for the sample without addition of ErAs Nps, clearly indicating the strong tunneling enhancement effect from ErAs Nps.

FABRICATION AND CHARACTERIZATION OF La2-xSrxCuO4/Nb-SrTiO3 HETEROJUNCTIONS IN DIFFERENT DOPED REGIMES

2012 ◽  
Vol 27 (01) ◽  
pp. 1350005 ◽  
Author(s):  
Y. ZHANG ◽  
G. F. WANG ◽  
W. L. LI ◽  
J. Q. SHEN ◽  
P. G. LI ◽  
...  
Keyword(s):  
Carrier Density ◽  
Pulsed Laser ◽  
Depletion Layer ◽  
Laser Deposition ◽  
Superconducting Gap ◽  
Applied Bias ◽  
Current Voltage ◽  
Fabrication And Characterization ◽  
The Difference

Two types of p–n junction were fabricated by depositing underdoped La 1.9 Sr 0.1 CuO 4 film and overdoped La 1.8 Sr 0.2 CuO 4 film on n -type 0.5 wt.% Nb -doped SrTiO 3 (NSTO) substrates using pulsed laser deposition technique (PLD), respectively. Current–voltage (I–V) characteristics of the La 2-x Sr x CuO 4/NSTO heterojunction were measured in the temperature range from 5 K to 300 K. All I–V curves show a fine rectifying property and a visible reduction of the diffusion potential (Vd) is observed, but the behaviors of Vd are vastly different for the underdoped and overdoped regimes at temperatures below Tc. Analysis results show that the characteristics of the heterojunction are possibly affected not only by the superconducting gap of LSCO at Tc, but also by the depletion layer in the interface of LSCO/NSTO junction. The variation of the depletion layer is possibly different under the same applied bias voltages for the underdoped La 1.9 Sr 0.1 CuO 4/NSTO junction and overdoped La 1.8 Sr 0.2 CuO 4/NSTO junction due to the difference of carrier density at La 1.9 Sr 0.1 CuO 4 and La 1.8 Sr 0.2 CuO 4.

Nanowire Arrays for Thermoelectric Devices

2003 ◽  
Author(s):  
Woo C. Kim ◽  
Alexis R. Abramson ◽  
Scott T. Huxtable ◽  
Arun Majumdar ◽  
Yiying Wu ◽  
...  
Keyword(s):  
Ohmic Contacts ◽  
Nanowire Arrays ◽  
Native Oxide ◽  
Thermoelectric Device ◽  
Growth Mechanisms ◽  
Thermoelectric Devices ◽  
Current Voltage ◽  
Semiconductor Junction ◽  
Fabrication And Characterization

This study reports on the fabrication and characterization of two prototype thermoelectric devices constructed of either silicon (Si) or bismuth telluride (Bi2Te3) nanowire arrays. The growth mechanisms and fabrication procedures of the Si and Bi2Te3 devices are different as described in this paper. To characterize the thermoelectric device components, current-voltage (I-V) characteristics were first used to estimate their performance. For the Si device, the I-V characteristics suggest ohmic contacts at the metal-semiconductor junction. For the Bi2Te3 device, the I-V characteristics curve showed a rectifying contact. Either low doping of the Bi2Te3 or surface contamination, i.e. native oxide, may cause the rectifying contact. The reversible Peltier effects occurring within the Si device were analyzed using a micro-thermocouple. Results indicated possible limitations of using Si nanowire arrays for the thermoelectric device.

Continuous electrical in situ contact area measurement during instrumented indentation

2008 ◽  
Vol 23 (9) ◽  
pp. 2480-2485 ◽  
Author(s):  
Lei Fang ◽  
Christopher L. Muhlstein ◽  
James G. Collins ◽  
Amber L. Romasco ◽  
Lawrence H. Friedman
Keyword(s):  
Contact Area ◽  
Dynamic Properties ◽  
Electrical Contact ◽  
Area Measurement ◽  
Analysis Method ◽  
Instrumented Indentation ◽  
Current Voltage ◽  
Indentation Tests

The primary tool for mechanical characterization of surfaces and films is instrumented indentation using the Oliver-Pharr data analysis method. However, this method measures contact area between the indenter and sample indirectly, thus confounding instrumented indentation tests when characterizing dynamic properties, thin films, and materials that “pileup” around the indenter. Here, we demonstrate an electrical technique to continuously measure the in situ contact area by relating nonlinear electrical contact current–voltage (I–V) curves to the instantaneous contact area. Using this approach, we can obtain hardness as a continuous function of applied force.

Design, fabrication and characterization of an electrical-explosively actuated MEMS flyer-accelerator inserted with parallel bridge foils

2020 ◽  
Vol 91 (1) ◽  
pp. 10301
Author(s):  
Zhi Yang ◽  
Guoqiang Zheng ◽  
Peng Zhu ◽  
Cong Xu ◽  
Qiu Zhang ◽  
...  
Keyword(s):  
High Speed ◽  
Electrical Explosion ◽  
Enhancement Effect ◽  
High Speed Camera ◽  
And Shock Waves ◽  
Test Circuit ◽  
Mems Technology ◽  
Fabrication And Characterization ◽  
Good Agreement

Parallel bridge foils (PBF) with four strip foils, which is derived from traditional single bridge foil (SBF), was designed to study the effect of convergence and collision of plasmas and shock waves on driving flyer. Firstly, Electro-thermal simulation of PBF was performed to analyze temperature distribution before melting, which predicted the synchronous burst characteristic of PBF. Subsequently, a capacitor discharging circuit was designed to initiate bridge foils, results indicated PBF reached higher burst power in shorter time compared with SBF due to better matching between PBF and the test circuit. The flow fields of electrical explosion of bridge foils were photographed by ultra-high-speed camera, which displayed PBF almost burst simultaneously. Moreover, PBF had wider and brighter flow field visualization than SBF owing to convergence and superposition of plasma beams. Most importantly, flyer-accelerators inserted with bridge foils were prepared by MEMS technology, and comparative analysis from PDV revealed MEMS flyer-accelerator inserted with PBF had access to better velocity performances, compared with that inserted with SBF. For instance, PBF flyer-accelerator spent mere 168 ns to 2325 m/s at 900 V/0.22 µF, but SBF flyer-accelerator took 335 ns to 1073 m/s. Finally, we proposed a mathematical model for explaining the enhancement effect of flyer velocity, which to some extent showed good agreement with experimentation.

Demonstration of Defect-Induced Limitations on the Properties of Au/3C-SiC Schottky Barrier Diodes

2009 ◽  
Vol 156-158 ◽  
pp. 331-336 ◽  
Author(s):  
Jens Eriksson ◽  
Ming Hung Weng ◽  
Fabrizio Roccaforte ◽  
Filippo Giannazzo ◽  
Stefano Leone ◽  
...  
Keyword(s):  
Contact Area ◽  
Schottky Diodes ◽  
Electrical Current ◽  
Contact Radius ◽  
Conductive Atomic Force Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Current Voltage ◽  
Capacitance Voltage

The electrical current-voltage (I-V) and capacitance-voltage (C-V) characteristics of Au/3C-SiC Schottky diodes were studied as a function of contact area. The results were correlated to defects in the 3C-SiC, which were studied and quantified by conductive atomic force microscopy (C-AFM). A method based on C-AFM was introduced that enables current-voltage characterization of diodes of contact radius down to 5 µm, which consequently allows the extraction of diode parameters for Schottky diodes of very small contact area.

ISOTYPE SnO2–Si HETEROJUNCTION MADE BY RAPID PHOTOTHERMAL OXIDATION OF Sn

2011 ◽  
Vol 25 (25) ◽  
pp. 3381-3389 ◽  
Author(s):  
RAID A. ISMAIL ◽  
MAHDI H. SHEEL ◽  
SA'AD GHAFORI
Keyword(s):  
Optical Transmission ◽  
Optical Transmittance ◽  
Electrical Measurement ◽  
Tetragonal Crystal ◽  
Current Voltage ◽  
Tetragonal Crystal Structure ◽  
Capacitance Voltage ◽  
Fabrication And Characterization ◽  
Two Peaks

We report on fabrication and characterization of SnO 2– Si n–n made by deposition of SnO 2 film onto monocrystalline silicon substrate by rapid photothermal oxidation (RPO) of Sn with condition 500°C/120 s. The film has been characterized by techniques such as XRD, optical transmission, and Hall effect. The XRD spectrum showed that the grown SnO 2 was polycrystalline in nature with tetragonal crystal structure. From optical transmittance data the band gap of SnO 2 film was calculated and found to be 3.9 eV. The electrical measurement revealed that the SnO 2 film was n-type. Current–voltage (I–V) and capacitance–voltage (C–V) characteristics of SnO 2– Si heterojunction were investigated. The ideality factor of junction estimated from I–V characteristics was 1.8 at 300 K. The spectral responsivity of heterojunction having two peaks of response located at 650 nm and 850 nm.

scholarly journals Fabrication and Characterization of Self-Powered Photosensor Based on Nanostructure TiO2/natural Dyes

2021 ◽  
Vol 2114 (1) ◽  
pp. 012055
Author(s):  
H.F. Al-Taay
Keyword(s):  
Natural Dyes ◽  
Voltage Sensitivity ◽  
Back Contact ◽  
Zero Bias ◽  
Glass Substrates ◽  
Nanostructured Thin Film ◽  
Current Voltage ◽  
Fabrication And Characterization ◽  
Self Powered

Abstract Self-powered photosensor is fabricated based on nanostructure TiO2/natural dyes. TiO2 nanostructured thin film was prepared on FTO/glass substrates by hydrothermal method. Surface morphology, crystalline structure, as well as optical properties of the prepared sample are investigated. Three types of natural dyes, pomegranate, aubergine, and coffee are used as an active layer (absorber) of the fabricated photosensor. However, the solution of dye was casted onto TiO2 and left to dry naturally and carbon/FTO was used as a back contact of the device. Current-voltage (I-V) characteristic under dark and light case was characterized for all prepared sensors. Besides, the fabricated sensors appeared good response to whit light under zero bias voltage. Sensitivity, raise and decay time of the prepared photosensor are calculated.

Fabrication and Characterization of Polyoxometalate based Nano-hybrids: Evaluation of their role in Biological Activity

2019 ◽  
Vol 35 (4) ◽  
pp. 475-484
Author(s):  
SHIVA ARUN ◽  
◽  
PRABHA BHARTIYA ◽  
AMREEN NAZ ◽  
SUDHEER RAI ◽  
...  
Keyword(s):  
Biological Activity ◽  
Fabrication And Characterization
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