Functional Characteristics of QD-InAs/GaAs Heterostructures with Potential Barriers AlGaAs and GaAs

2018 ◽  
Vol 284 ◽  
pp. 182-187
Author(s):  
E.E. Blokhin ◽  
D.A. Arustamyan ◽  
L.M. Goncharova
Keyword(s):  
Quantum Dots ◽  
High Speed ◽  
Ion Beam ◽  
Inas Quantum Dots ◽  
Potential Barriers ◽  
Near Ir ◽  
Current Voltage ◽  
Ir Photodetectors ◽  
Current Voltage Characteristics ◽  
Beam Deposition

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.

scholarly journals Variation of the photoluminescence spectrum of InAs/GaAs heterostructures grown by ion-beam deposition

2018 ◽  
Vol 9 ◽  
pp. 2794-2801 ◽  
Author(s):  
Alexander S Pashchenko ◽  
Leonid S Lunin ◽  
Eleonora M Danilina ◽  
Sergei N Chebotarev
Keyword(s):  
Quantum Dots ◽  
Ion Beam ◽  
Inas Quantum Dots ◽  
Potential Barriers ◽  
Barrier Layers ◽  
Ion Beam Deposition ◽  
Gaas Barrier ◽  
Isovalent Doping ◽  
Photoluminescence Peak ◽  
Beam Deposition

This work reports on an experimental investigation of the influence of vertical stacking of quantum dots, the thickness of GaAs potential barriers, and their isovalent doping with bismuth on the photoluminescence properties of InAs/GaAs heterostructures. The experimental samples were grown by ion-beam deposition. We showed that using three vertically stacked layers of InAs quantum dots separated by thin GaAs barrier layers was accompanied by a red-shift of the photoluminescence peak of InAs/GaAs heterostructures. An increase in the thickness of the GaAs barrier layers was accompanied by a blue shift of the photoluminescence peak. The effect of isovalent Bi doping of the GaAs barrier layers on the structural and optical properties of the InAs/GaAs heterostructures was investigated. It was found that the Bi content up to 4.96 atom % in GaAs decreases the density of InAs quantum dots from 1.53 × 1010 to 0.93 × 1010 cm−2. In addition, the average lateral size of the InAs quantum dots increased from 14 to 20 nm, due to an increase in the surface diffusion of In. It is shown that isovalent doping of GaAs potential barriers by bismuth was accompanied by a red-shift of the photoluminescence peak of InAs quantum dots of 121 meV.

Enhanced photocurrent due to interband transitions from InAs quantum dots embedded in InGaAs quantum well solar cells

2013 ◽  
Vol 1551 ◽  
pp. 143-148
Author(s):  
R. Vasan ◽  
Y. F. M. Makableh ◽  
J. C. Sarker ◽  
M. O. Manasreh
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Open Circuit Voltage ◽  
Spectral Response ◽  
Power Conversion ◽  
Open Circuit ◽  
Interband Transitions ◽  
Inas Quantum Dots ◽  
Current Voltage ◽  
Current Voltage Characteristics

ABSTRACTSolar cells based on InAs quantum dots embedded in InxGa1-xAs quantum wells grown on n-type GaAs substrate were fabricated and tested. Solar cells with In mole fraction (x) in the range of 0-40% were investigated. The performance of the solar cells was evaluated using current-voltage characteristics, spectral response, and quantum efficiency measurements. The spectral response and quantum efficiency spectra possess several peaks along the lower energy side of the spectra, which are attributed to the interband transitions in the structure. These peaks are red shifted as x is increased above 0 %. The device power conversion efficiency was extracted from the current-voltage characteristics using an AM 1.5 solar simulator. The short circuit current density increased as the x is increased above 0 %. But the overall power conversion efficiency decreased due to decrease in the open circuit voltage. The decrease in open circuit voltage is due strain induced dislocations caused by lattice mismatch.

Current/voltage characteristics of ion beam synthesised CoSi2/Si Schottky barrier diodes

1992 ◽  
Vol 28 (3) ◽  
pp. 296 ◽  
Author(s):  
R.S. Spraggs ◽  
G. Pananakakis ◽  
D. Bauza ◽  
K.J. Reeson ◽  
B.J. Sealy
Keyword(s):  
Schottky Barrier ◽  
Ion Beam ◽  
Schottky Barrier Diodes ◽  
Current Voltage ◽  
Current Voltage Characteristics

scholarly journals Electron Spectrum and Tunneling Current of the Toroidal and Helical Graphene Nanoribbon-Quantum Dots Contact

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Mikhail B. Belonenko ◽  
Nikolay G. Lebedev ◽  
Alexander V. Zhukov ◽  
Natalia N. Yanyushkina
Keyword(s):  
Quantum Dots ◽  
Dirac Equation ◽  
Density Of States ◽  
Electron Spectrum ◽  
Tunneling Current ◽  
Graphene Nanoribbon ◽  
Curved Space ◽  
Long Wave ◽  
Current Voltage ◽  
Current Voltage Characteristics

We study the electron spectrum and the density of states of long-wave electrons in the curved graphene nanoribbon based on the Dirac equation in a curved space-time. The current-voltage characteristics for the contact of nanoribbon-quantum dot have been revealed. We also analyze the dependence of the specimen properties on its geometry.

scholarly journals Влияние контактной разности потенциалов на вольт-амперные характеристики в сканирующей туннельной спектроскопии

2021 ◽  
Vol 91 (11) ◽  
pp. 1769
Author(s):  
М.В. Кузьмин ◽  
М.А. Митцев
Keyword(s):  
Contact Potential Difference ◽  
Scanning Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Differential Conductivity ◽  
Contact Potential ◽  
Potential Barriers ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Work Functions ◽  
Conductivity Spectra

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.

Mechanisms of negative differential resistance in glutamine-functionalized WS2 quantum dots

2021 ◽  
Author(s):  
Denice Feria ◽  
Sonia Sharma ◽  
Yu-Ting Chen ◽  
Zhi-Ying Weng ◽  
Kuo-Pin Chiu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Negative Differential Resistance ◽  
Electronic Devices ◽  
Transition Metal Dichalcogenides ◽  
Differential Resistance ◽  
Voltage Range ◽  
Current Voltage ◽  
Metal Dichalcogenides ◽  
Current Voltage Characteristics ◽  
Memory Applications

Abstract Understanding the mechanism of the negative differential resistance (NDR) in transition metal dichalcogenides is essential for fundamental science and the development of electronic devices. Here, the NDR of the current-voltage characteristics was observed based on the glutamine-functionalized WS2 quantum dots (QDs). The NDR effect can be adjusted by varying the applied voltage range, air pressure, surrounding gases, and relative humidity. A peak-to-valley current ratio as high as 6.3 has been achieved at room temperature. Carrier trapping induced by water molecules was suggested to be responsible for the mechanism of the NDR in the glutamine-functionalized WS2 QDs. Investigating the NDR of WS2 QDs may promote the development of memory applications and emerging devices.

Photosensitive Amorphous Si Thin Films Prepared by Magnetron Technology.

2002 ◽  
Vol 744 ◽  
Author(s):  
Galina Khlyap ◽  
Victor Brytan
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Continuous Mode ◽  
Applied Bias ◽  
Near Ir ◽  
Current Voltage ◽  
Exponential Character ◽  
Current Voltage Characteristics ◽  
Amorphous Si ◽  
Spectral Ranges

ABSTRACTElectric field – induced effects are studied in thin films of amorphous Si grown by magnetron sputtering performed in continuous and pulse modes. Current-voltage characteristics are measured under the room temperature in different spectral ranges. It is shown that the investigated dependencies are of exponential character in all range of applied bias. Good photosensitivity was revealed by the samples prepared in continuous mode in the near-IR and visible interval. The samples grown by the pulse magnetron technology were shown room-temperature photosensitivity in near-IR range after 2000C hydrogenation.

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