scholarly journals Obtaining and doping of InAs-QD/GaAs(001) nanostructures by ion beam sputtering

2017 ◽  
Vol 8 ◽  
pp. 12-20 ◽  
Author(s):  
Sergei N Chebotarev ◽  
Alexander S Pashchenko ◽  
Leonid S Lunin ◽  
Elena N Zhivotova ◽  
Georgy A Erimeev ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Ion Beam ◽  
Beam Current ◽  
Growth Direction ◽  
Ion Beam Sputtering ◽  
Inas Quantum Dots ◽  
Spacer Layer ◽  
Gaas Barrier ◽  
Beam Sputtering ◽  
Impurity Doping

The features of InAs quantum dots obtained on GaAs(001) single-crystal substrates by ion-beam sputtering were investigated. It has been shown that in the range of ion energies of 150 to 200 eV at a temperature of 500 °C and a beam current of 120 µA InAs quantum dots with average dimensions below 15 nm and a surface density of 1011 cm−2 are formed. The technique of controlled doping of InAs/GaAs nanostructures using a SnTe solid-state source was proposed. It has been established that a maximum donor concentration of 8.7·1018 cm−3 in the GaAs spacer layer is reached at an evaporation temperature of 415 °С. At the same time, impurity accumulation in the growth direction was observed. We have shown that increasing the impurity doping of the GaAs barrier layer increases the intensity of photoluminescence peaks of the ground state and the first excited state of the InAs quantum dots.

scholarly journals Morphology and Optical Investigations of InAs-QD/GaAs Heterostructures Obtained by Ion-Beam Sputtering

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
S. N. Chebotarev ◽  
A. S. Pashchenko ◽  
V. A. Irkha ◽  
M. L. Lunina
Keyword(s):  
Quantum Dots ◽  
Ion Beam ◽  
Beam Current ◽  
High Dispersion ◽  
Ion Beam Sputtering ◽  
Inas Quantum Dots ◽  
Atomic Force ◽  
Beam Sputtering ◽  
Very High ◽  
A Current

A new ion-beam sputtering technique for obtaining self-assembled InAs quantum dots on GaAs (001) substrates is proposed. The current paper demonstrates that a temperature increase in a range from 450 to 550°C at ion current of 120 μA and energy of 150 eV leads to an expansion of average sizes of InAshut-quantum dots. According to atomic force and electron microscopy, photoluminescence, and capacity-voltage measurements it was found that an increase of ion-beam current from 60 to 120 μA at a temperature of 500°C and energy of 150 eV slightly enlarges the average sizes of quantum dots from 15 nm to 18 nm while their dispersion is about 30%. At a current of 180 μA a surface density is1.3·1011 cm−2, but under these conditions there is a very high dispersion of quantum dots up to 50%.

Effects of Si Spacer-Layer on the Structure of Ge/Si Quantum Dots Bilayers Grown by Ion Beam Sputtering

2013 ◽  
Vol 873 ◽  
pp. 479-485
Author(s):  
Xi Zhou ◽  
Chong Wang ◽  
Jie Yang ◽  
Ying Xia Jin ◽  
Yu Yang
Keyword(s):  
Quantum Dots ◽  
Double Layer ◽  
Ion Beam ◽  
Ion Beam Sputtering ◽  
Sputtering Deposition ◽  
Si Quantum Dot ◽  
Spacer Layer ◽  
Beam Sputtering ◽  
Factor Interactions ◽  
Si Quantum Dots

A series of double-layer Ge/Si quantum dots are prepared by ion beam sputtering deposition (IBSD) on Si (100) substrates. The influences of deposition temperature and thickness of Si spacer-layer on the microstructure of double-layer Ge/Si quantum dots were characterized by using Atomic force microscopy (AFM) and Raman spectra technique. The results indicate that the density of the second layer islands firstly increases and then decreases with increasing the growth temperature of Si spacer-layers. In addition, increasing the thickness of Si spacer-layer, the islands merger phenomenon disappears. When the deposition thickness is larger than 40 nm, the islands on the upper-layer show the same features with the buried islands. The mechanism of three-factor-interactions of nanoislands is proposed to explain these phenomena, and our results can be used as a guidance to obtain optimum IBSD growth process for Ge/Si quantum-dot superlattices.

Fabrication of Ge quantum dots doped TiO2 films with high optical absorption properties via layer-by-layer ion-beam sputtering

2012 ◽  
Vol 67 (1) ◽  
pp. 369-372 ◽  
Author(s):  
Xiaoqing Li ◽  
Fang He ◽  
Guigao Liu ◽  
Yuan Huang ◽  
Chengfu Pan ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optical Absorption ◽  
Ion Beam ◽  
Layer By Layer ◽  
Tio2 Films ◽  
Ion Beam Sputtering ◽  
Absorption Properties ◽  
Doped Tio2 ◽  
Beam Sputtering ◽  
High Optical Absorption

High Resolution Backscatter Electron (BSE) Imaging using the Autrata Modified YAG BSE Detector: Comparison of an In-lens Hitachi S-900 FESEM with the Below-the-Lens Hitachi S-4700 FESEM

2001 ◽  
Vol 7 (S2) ◽  
pp. 1046-1047
Author(s):  
Stanley L. Erlandsen ◽  
Ya Chen ◽  
Chris Frethem
Keyword(s):  
High Resolution ◽  
Colloidal Gold ◽  
Ion Beam ◽  
Beam Current ◽  
Backscatter Electron ◽  
Ion Beam Sputtering ◽  
Gold Particles ◽  
Lens Position ◽  
Beam Sputtering ◽  
Working Distance

To obtain high resolution backscatter electron (BSE) images in field emission SEM (FESEM), one must consider selection of accelerating voltage, beam current, working distance between the specimen and the backscatter detector (in-lens or below-the-lens position for the specimen), the type of BSE detector, and the type of metal used to coat the specimen to improve conductivity and signal collection [1]. A new generation of below-the-lens FESEM have been tested for BSE imaging on biological samples, but no information exists on whether or not high resolution imaging is possible. Here we report the comparison of detection of a colloidal gold standard (6, 12, 18 nm) by high resolution BSE imaging using Autrata-modified YAG detectors in an in-lens FESEM and in a below-the-lens FESEM.Standards were prepared by mixing colloidal gold particles of 6 nm, 12 nm, and 18 nm. The gold particles were attached via poly-l-lysine to glass chips and coated with <1 nm Pt by ion beam sputtering.

scholarly journals Underlying strain-induced growth of the self-assembled Ge quantum-dots prepared by ion beam sputtering deposition

2012 ◽  
Vol 61 (1) ◽  
pp. 016804
Author(s):  
Yang Jie ◽  
Wang Chong ◽  
Jin Ying-Xia ◽  
Li Liang ◽  
Tao Dong-ping ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Ion Beam ◽  
The Self ◽  
Ion Beam Sputtering ◽  
Sputtering Deposition ◽  
Beam Sputtering ◽  
Ge Quantum Dots ◽  
Self Assembled

scholarly journals Evolution of Ge/Si quantum dots self-assembledgrown by ion beam sputtering

2011 ◽  
Vol 60 (9) ◽  
pp. 096101
Author(s):  
Zhang Xue-Gui ◽  
Wang Chong ◽  
Lu Zhi-Quan ◽  
Yang Jie ◽  
Li Liang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Ion Beam ◽  
Ion Beam Sputtering ◽  
Beam Sputtering ◽  
Si Quantum Dots

The Characterization of CIGS Thin Films Prepared by Ion Beam Sputtering Deposition from a Quaternary Target

2013 ◽  
Vol 734-737 ◽  
pp. 2545-2548
Author(s):  
Chao Ming Chen ◽  
Ping Fan ◽  
Guang Xing Liang ◽  
Zhuang Hao Zheng ◽  
Dong Ping Zhang ◽  
...  
Keyword(s):  
Thin Films ◽  
Ion Beam ◽  
Hall Effect Measurement ◽  
Beam Current ◽  
Chalcopyrite Structure ◽  
Ion Beam Sputtering ◽  
Sputtering Deposition ◽  
X Ray ◽  
Beam Sputtering ◽  
Beam Currents

This study reports the successful preparation of Cu (In, Ga)Se2(CIGS) thin film solar cells by ion beam sputtering with a chalcopyrite CIGS quaternary target. The films were fabricated with different beam currents. The thin films were characterized with X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM) and hall effect-measurement system to study the microstructures, composition, surface morphology and electrical properties, respectively. Experimental results show that both the films are chalcopyrite structure, the Ga/(In+Ga) ratio, Cu/(In+Ga) ratio and Se/(Cu+In+Ga) ratio are decrease with the beam currents increase, the surfaces morphology of the films are dense, and the resistivity of the film deposited with the beam current of 40mA is 0.56Ωcm, with a carrier concentration of 4.11Χ1018cm-3and mobility of 2.73cm2V-1s-1. The resulting film exhibited p-type conductivity.

scholarly journals Quantum Dots: An Emerging Approach for Cancer Therapy

2022 ◽  
Vol 8 ◽  
Author(s):  
Sheetal Devi ◽  
Manish Kumar ◽  
Abhishek Tiwari ◽  
Varsha Tiwari ◽  
Deepak Kaushik ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Ion Beam ◽  
Atomic Layer ◽  
Present Review ◽  
Layer By Layer ◽  
Ion Beam Sputtering ◽  
Photodynamic Treatment ◽  
Sputtering Deposition ◽  
Beam Sputtering ◽  
Fundamental Insight

Nanotechnology is indisputably a scientific technique that offers the prospect of new therapies, and hope, for the treatment of malignant illnesses. It is a novel technology that offers new approaches for the diagnosis and management of diverse diseases. Although the discovery of Quantum dots (QD) nano-transporters has already led to a few positive developments, QD nano-transporters are still at their initial stage, though have yet proven valuable to society. The excertion of QD indicates conversion in natural imaging along with photograph have established incredible suitability in bio-imaging, new drug development, targeted gene deliverance, biosensing, photodynamic treatment as well as diagnosis. The present review aimed to confer the significance of QD in diagnosis as well as in management of cancer. This review aims to impart fundamental insight as well as conception of QD its merits, properties, utilization as well as mode of action. This review highlight of different designing schemes of QD like hydrothermal, drop-casting, ultrasonic, solvothermal, spin-coating, atomic layer desorption, layer by layer, polymethylmethacrylate aided-transfer, electrochemical, ion beam sputtering deposition. Moreover, we have elaborated on the diverse researches related to cytotoxic examination to reveal that QDs are harmless. Concisely, the present review summarizes the fabrication schemes, current research and utilization of QD in cancer treatment.

scholarly journals Nanostructures on Sapphire Surfaces Induced by Metal Impurity Assisted Ion Beam

Coatings ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 949 ◽  
Author(s):  
Qian Bi ◽  
Zhili Chen ◽  
Yuzhao Liu ◽  
Li Tang ◽  
Yingxue Xi ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Ion Beam ◽  
Beam Current ◽  
Beam Current Density ◽  
Angle Of Incidence ◽  
Ion Beam Sputtering ◽  
Metal Impurity ◽  
Metal Impurities ◽  
Ripple Formation ◽  
Beam Sputtering

The metal impurity assisted ion beam technology has shown its uniqueness and effectiveness in the formation and precise control of nanostructures on the surface of materials. Hence, the investigation in this area is vital. The morphology evolution of self-organized nanostructures induced by Fe co-deposition assisted Ar+ ion beam sputtering at a different distance from the impurity target was investigated on sapphire, using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). We also investigated the role of metal impurities on sapphire ripple formation. Experiments were carried out at an oblique angle of incidence 65° with constant ion beam current density 487 μA/cm2 and the erosion duration of 60 min at room temperature (20 °C). The introduction of Fe impurity increased the longitudinal height and roughness of the surface nanostructures. Moreover, the amounts of Fe deposited on the surface decreased with increasing distance, and the morphology of the smooth sapphire surface demonstrated a strong distance dependence. Differences in surface morphology were attributed to changes in metal impurity concentration. With an increase of impurity target distance, island-like structures gradually evolved into continuous ripples. At the same time, the orderliness of nanostructures was enhanced, the longitudinal height gradually decreased, while the spatial frequency was unchanged. In addition, there were very few metal impurities on the etched sample. During the ion beam sputtering process, island-like structures promoted the growth of ripples but destroyed their orderliness.

Deposition amount effects on the microstructure of ion-beam-sputtering grown Mn0.03Ge0.97 quantum dots for spintronic applications

2020 ◽  
Author(s):  
Yahui Li ◽  
Chen Li ◽  
Haochen Tong ◽  
Tao Chen ◽  
Guangyang Li ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Ion Beam ◽  
Ion Beam Sputtering ◽  
Deposition Amount ◽  
Beam Sputtering
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