Electronic energy levels and energy relaxation mechanisms in self-organized InAs/GaAs quantum dots

1996 ◽  
Vol 54 (24) ◽  
pp. 17738-17744 ◽  
Author(s):  
M. J. Steer ◽  
D. J. Mowbray ◽  
W. R. Tribe ◽  
M. S. Skolnick ◽  
M. D. Sturge ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Energy Levels ◽  
Energy Relaxation ◽  
Electronic Energy ◽  
Self Organized ◽  
Electronic Energy Levels

ELECTRON-ENERGY RELAXATION IN POLAR SEMICONDUCTOR DOUBLE QUANTUM DOTS

2001 ◽  
Vol 15 (27) ◽  
pp. 3503-3512 ◽  
Author(s):  
K. KRÁL ◽  
Z. KHÁS ◽  
P. ZDENĚK ◽  
M. ČERŇANSKÝ ◽  
C. Y. LIN
Keyword(s):  
Quantum Dots ◽  
Relaxation Rate ◽  
Phonon Scattering ◽  
Energy Levels ◽  
Realistic Model ◽  
Energy Relaxation ◽  
Electronic Energy ◽  
Double Quantum ◽  
Quantum Bit ◽  
Electronic Energy Levels

The zero-dimensional semiconductor nanostructures belong to the candidates for the realization of the quantum bits. They are expected to be scalable for the purpose of tuning their physical properties. In these structures the quantum bit could be realized in the form of a single quantum dot with two electronic energy levels, with only one electron in the dot. As the basic states of the quantum bit, realized in this way, the two orbital states of the electron in the dot could be used. It appears however that usually the relaxation of the energy of the electron from the excited energy level is often rather fast in the polar semiconductor quantum dots. It is the purpose of this paper to present calculations of the relaxation rate of the electron in an asymmetric pair of tunneling coupled quantum dots, in which the two electronic orbitals of the quantum bit are located each in a separate dot. The calculation of the electronic energy relaxation is based on the multiple electron-LO-phonon scattering processes, implemented to the theory via the electronic self-energy taken in the self-consistent Born approximation. The dependence of the relaxation rate on the geometry of the pair of the coupled dots and on the lattice temperature is presented for a realistic model of this nanostructure.

Biologically Engineered Quantum Dots for Biomedical Applications

2008 ◽  
Vol 1095 ◽  
Author(s):  
Ganna Chornokur ◽  
Sergei Ostapenko ◽  
Yusuf Emirov ◽  
Nadezhda Korsunska ◽  
Abraham Wolcott ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Energy Levels ◽  
Local Stress ◽  
Blue Shift ◽  
Spectral Shift ◽  
Electronic Energy ◽  
Transmission Electron ◽  
Solid Substrates ◽  
Electronic Energy Levels ◽  
Electrophoresis Technique

AbstractWe report on a short-wavelength, “blue” spectral shift of the photoluminescence (PL) spectrum in CdSeTe/ZnS core/shell quantum dots (QDs) caused by bioconjugation with several monoclonal cancer related antibodies (ABs). Scanning PL spectroscopy was performed on samples dried on solid substrates at various temperatures. The influence of the AB chemical origin on the PL spectral shift was observed. The conjugation QD-AB reaction was confirmed using the agarose gel electrophoresis technique. The spectral shift is strongly increased and the process facilitated when the samples are dried above room temperature. The PL spectroscopic mapping revealed a profile of the PL spectral shift across the dried QD-AB spot. Transmission Electron Microscopy analyses of the samples were performed to reveal the shape and size of individual QDs. A mechanism of the “blue” shift is attributed to changes in the QD electronic energy levels caused by local stress field applied to the bio-conjugated QD.

Electronic Energy Levels in an Asymmetric Quantum-Dots-in-a-Well Structure for Infrared Photodetectors

2008 ◽  
Vol 25 (7) ◽  
pp. 2645-2648 ◽  
Author(s):  
Wang Zhi-Cheng ◽  
Xu Bo ◽  
Chen Yong-Hai ◽  
Shi Li-Wei ◽  
Liang Zhi-Mei ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Energy Levels ◽  
Electronic Energy ◽  
Infrared Photodetectors ◽  
Asymmetric Quantum ◽  
Electronic Energy Levels ◽  
Asymmetric Quantum Dots

A consolidated account of electrochemical determination of band structure parameters in II–VI semiconductor quantum dots: a tutorial review

2019 ◽  
Vol 21 (9) ◽  
pp. 4695-4716 ◽  
Author(s):  
Pravin Popinand Ingole
Keyword(s):  
Quantum Dots ◽  
Band Structure ◽  
Electronic Band Structure ◽  
Energy Levels ◽  
Electrochemical Determination ◽  
Electronic Energy ◽  
Semiconductor Quantum Dots ◽  
Electronic Band ◽  
Nano Structure ◽  
Electronic Energy Levels

Probing absolute electronic energy levels in semiconductor quantum dots (Q-dots) is crucial for engineering their electronic band structure and hence for precise design of composite nano-structure based devices.

STRAIN DISTRIBUTION AND ELECTRONIC STRUCTURE OF SELF-ORGANIZED InAs/GaAs QUANTUM DOTS

2009 ◽  
Vol 18 (04) ◽  
pp. 553-560
Author(s):  
YUMIN LIU ◽  
ZIHUAN XU ◽  
ZHONGYUAN YU ◽  
BOYONG JIA ◽  
WENJUAN LU ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Electronic Structure ◽  
Quantum Dot ◽  
Strain Distribution ◽  
Energy Levels ◽  
Electronic Energy ◽  
Conduction Band Edge ◽  
Three Dimension ◽  
Self Organized ◽  
Piezoelectric Effects

This paper presents a finite element method for calculating the strain distribution, piezoelectric effects and their influences on the electronic structure of self-organized InAs/GaAs quantum dots. The models used for strain calculations are based on the continuum elastic theory, which is capable of treating the quantum dot of arbitrary shapes. A truncated pyramid shaped quantum dot model including the wetting layer is adopted in this work. The electronic energy levels of the InAs/GaAs systems are calculated by solving the three-dimension effective mass Schrödinger equation including the influences on the modification of conduction band edge due to the strain and piezoelectricity. The calculated results indicate that both strain and piezoelectric effects should be considered, especially in treating the electronic structure and optical characteristics for device applications.

Optoelectronic Device Applications of Self-Organized In(Ga,Al)As/Ga(Al)As Quantum Dots

2000 ◽  
Vol 618 ◽  
Author(s):  
P. Bhatiacharya ◽  
S. Krishna ◽  
D. Zhu ◽  
J. Phillips ◽  
D. Klotzkin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
High Speed ◽  
Energy Levels ◽  
Relaxation Times ◽  
Optoelectronic Device ◽  
Infrared Emission ◽  
Electronic Energy ◽  
Tunneling Time ◽  
Self Organized ◽  
Electro Optic

ABSTRACTSelf-organized growth of strained semiconductor heterostructures has enabled the realization of ordered arrays of quantum dots that can be incorporated into the active region of electronic and optoelectronic devices. Highly uniform In(Ga)As/Ga(Al)As with greatly reduced photoluminescence linewidths (FWHM=19 meV, T=17K) have been grown and characterized. Various aspects of carrier dynamics in these dots, such as measurement of carrier relaxation times and the modulation bandwidths of quantum dot lasers, estimation of the tunneling time in vertically coupled dots along with tuning of the intersubband electronic energy levels have also been studied. The favorable relaxation times can be exploited to realize far infrared emission and detection based on intersubband transitions in the dots. The optoelectronic properties of the dots and the dynamics of carriers therein are also extremely attractive for high-speed wavelength switching and the design of electro-optic modulators. The electro-optic coefficients in the quantum dots have been measured and the linear E-O coefficient, r1 =2.6 ×10−11m/V, is found to be comparable to that in LiNbO3

Sign in / Sign up

Export Citation Format

Share Document