Three-Dimensional Control of Self-Assembled Quantum Dot Configurations

ACS Nano ◽  
2010 ◽  
Vol 4 (7) ◽  
pp. 3877-3882 ◽  
Author(s):  
Michael K. Yakes ◽  
Cory D. Cress ◽  
Joseph G. Tischler ◽  
Allan S. Bracker
Keyword(s):  
Quantum Dot ◽  
Three Dimensional ◽  
Dimensional Control ◽  
Self Assembled

scholarly journals Spontaneous Self-Embedding of Three-Dimensional SiGe Islands

1999 ◽  
Vol 571 ◽  
Author(s):  
E. Mateeva ◽  
P. Sutter ◽  
M. G. Lagally
Keyword(s):  
Quantum Dot ◽  
Matrix Material ◽  
Three Dimensional ◽  
Self Assembled

ABSTRACTIt is shown that. under appropriate conditions, high-Ge-concentration coherent 3D SiGe islands grown on Si(100) self-embed in a matrix of low-Ge-concentration alloy. The process may be more generally useful for preserving the shape of self-assembled “quantum dot” islands during embedding in a matrix material.

Size and Piezoelectric Effects on Optical Properties of Self-Assembled InGaAs/GaAs Quantum Dots

2006 ◽  
Author(s):  
M. K. Kuo ◽  
T. R. Lin ◽  
K. B. Hong
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Quantum Dot ◽  
Optical Transition ◽  
Energy Levels ◽  
Three Dimensional ◽  
Dinger Equation ◽  
Element Analysis ◽  
Piezoelectric Effects ◽  
Self Assembled

Size effects on optical properties of self-assembled quantum dots are analyzed based on the theories of linear elasticity and of strain-dependent k-p with the aid of finite element analysis. The quantum dot is made of InGaAs with truncated pyramidal shape on GaAs substrate. The three-dimensional steady-state effective-mass Schro¨dinger equation is adopted to find confined energy levels as well as wave functions both for electrons and holes of the quantum-dot nanostructures. Strain-induced as well as piezoelectric effects are taken into account in the carrier confinement potential of Schro¨dinger equation. The optical transition energies of quantum dots, computed from confined energy levels for electrons and holes, are significantly different for several quantum dots with distinct sizes. It is found that for QDs with the the larger the volume of QD is, the smaller the values of the optical transition energy. Piezoelectric effect, on the other hand, splits the p-like degeneracy for the electron first excited state about 1~7 meV, and leads to anisotropy on the wave function.

Kinetic Monte Carlo simulations of three-dimensional self-assembled quantum dot islands

2014 ◽  
Vol 23 (1) ◽  
pp. 016802
Author(s):  
Xin Song ◽  
Hao Feng ◽  
Yu-Min Liu ◽  
Zhong-Yuan Yu ◽  
Hao-Zhi Yin
Keyword(s):  
Monte Carlo ◽  
Quantum Dot ◽  
Monte Carlo Simulations ◽  
Kinetic Monte Carlo ◽  
Three Dimensional ◽  
Kinetic Monte Carlo Simulations ◽  
Self Assembled

Graphene quantum dot-functionalized three-dimensional ordered mesoporous ZnO for acetone detection toward diagnosis of diabetes

Nanoscale ◽  
2019 ◽  
Vol 11 (24) ◽  
pp. 11496-11504 ◽  
Author(s):  
Wei Liu ◽  
Xiangyu Zhou ◽  
Lin Xu ◽  
Shidong Zhu ◽  
Shuo Yang ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Three Dimensional ◽  
Graphene Quantum Dot ◽  
Ordered Mesoporous ◽  
Highly Sensitive ◽  
Sensitive Sensor ◽  
Mesoporous Zno ◽  
Self Assembled ◽  
Acetone Detection

Self-assembled GQD-modified 3DOM ZnO was developed as a highly sensitive sensor for trace acetone detection toward the diagnosis of diabetes.

Temperature and Size Effects on the Extremely Low Thermal Conductivity of Self-assembled Germanium Quantum-dot Supercrystals in Silicon

2010 ◽  
Vol 1267 ◽  
Author(s):  
Jean-Numa Gillet
Keyword(s):  
Thermal Conductivity ◽  
Quantum Dot ◽  
Phonon Scattering ◽  
Lattice Mismatch ◽  
Average Distance ◽  
Near Field ◽  
Phononic Crystal ◽  
Three Dimensional ◽  
Atomic Scale ◽  
Self Assembled

AbstractDesign of semiconducting nanomaterials with an indirect electronic bandgap is currently one of the major areas of research to obtain a high thermoelectric yield by lowering their lattice thermal conductivity. Intensive investigations on superlattices were performed to achieve this goal. However, like one-dimensional nanowires, they decrease heat transport in only one propagation direction of the phonons. Moreover, they often lead to dislocations since they are composed of layered materials with a lattice mismatch. Design of superlattices with a thermoelectric figure of merit ZT higher than unity is therefore hazardous. Self-assembly of epitaxial layers on silicon has been used for bottom-up synthesis of three-dimensional (3D) Ge quantum-dot (QD) arrays in Si for quantum-device and solar-energy applications. Using the atomic-scale 3D phononic crystal model, it is predicted that high-density 3D arrays of self-assembled Ge QDs in Si can as well show an extreme reduction of the thermal transport. 3D supercrystals of Ge QDs in Si present a thermal conductivity that can be as tiny as that of air. These extremely low values of the thermal conductivity are computed for a number of Ge filling ratios and size parameters of the 3D Si-Ge supercrystal. Owing to incoherent phonon scattering with predominant near-field effects, the same conclusion holds for supercrystals with moderate QD disordering. As a result, design of highly-efficient CMOS-compatible thermoelectric devices with ZT possibly much higher than unity might be possible. In this theoretical study, simultaneous evolution of both temperature and average distance between the Ge QDs is analyzed for a non-variable Ge filling ratio to obtain thermal-conductivity values as low as that of air (+/- 0.025 W/m/K).

Nanoscale Self-Assembly Using Ion and Electron Beam Techniques: A Rapid Review

MRS Advances ◽  
2020 ◽  
Vol 5 (64) ◽  
pp. 3507-3520
Author(s):  
Chunhui Dai ◽  
Kriti Agarwal ◽  
Jeong-Hyun Cho
Keyword(s):  
Electron Beam ◽  
Self Assembly ◽  
Ion Beam ◽  
Three Dimensional ◽  
The Self ◽  
Stress Generation ◽  
Rapid Review ◽  
High Yield ◽  
3D Nanostructures ◽  
Self Assembled

AbstractNanoscale self-assembly, as a technique to transform two-dimensional (2D) planar patterns into three-dimensional (3D) nanoscale architectures, has achieved tremendous success in the past decade. However, an assembly process at nanoscale is easily affected by small unavoidable variations in sample conditions and reaction environment, resulting in a low yield. Recently, in-situ monitored self-assembly based on ion and electron irradiation has stood out as a promising candidate to overcome this limitation. The usage of ion and electron beam allows stress generation and real-time observation simultaneously, which significantly enhances the controllability of self-assembly. This enables the realization of various complex 3D nanostructures with a high yield. The additional dimension of the self-assembled 3D nanostructures opens the possibility to explore novel properties that cannot be demonstrated in 2D planar patterns. Here, we present a rapid review on the recent achievements and challenges in nanoscale self-assembly using electron and ion beam techniques, followed by a discussion of the novel optical properties achieved in the self-assembled 3D nanostructures.

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