Nanometer-scale measurements of electronic states in InAs∕GaAs quantum dots

V. D. Dasika; R. S. Goldman; J. D. Song; W. J. Choi; N. K. Cho; J. I. Lee

doi:10.1063/1.3158560

Nanometer-scale measurements of electronic states in InAs∕GaAs quantum dots

Journal of Applied Physics ◽

10.1063/1.3158560 ◽

2009 ◽

Vol 106 (1) ◽

pp. 014315 ◽

Cited By ~ 9

Author(s):

V. D. Dasika ◽

R. S. Goldman ◽

J. D. Song ◽

W. J. Choi ◽

N. K. Cho ◽

...

Keyword(s):

Quantum Dots ◽

Electronic States ◽

Nanometer Scale

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Electronic states of graphene quantum dots induced by nanobubbles

Journal of the Korean Physical Society ◽

10.1007/s40042-021-00196-x ◽

2021 ◽

Author(s):

Hee Chul Park ◽

Minsol Son ◽

Seung Joo Lee ◽

Nojoon Myoung

Keyword(s):

Quantum Dots ◽

Graphene Quantum Dots ◽

Electronic States

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SPACE-CHARGE SPECTROSCOPY OF ELECTRONIC STATES IN Ge/Si QUANTUM DOTS WITH TYPE-II BAND ALIGNMENT

International Journal of Nanoscience ◽

10.1142/s0219581x07004511 ◽

2007 ◽

Vol 06 (05) ◽

pp. 353-356

Author(s):

A. I. YAKIMOV ◽

A. V. DVURECHENSKII ◽

A. I. NIKIFOROV ◽

A. A. BLOSHKIN

Keyword(s):

Quantum Dots ◽

Electronic Structure ◽

Binding Energy ◽

Space Charge ◽

Tensile Strain ◽

Electronic States ◽

Band Alignment ◽

Type Ii ◽

Electron Confinement ◽

Si Quantum Dots

Space-charge spectroscopy was employed to study electronic structure in a stack of four layers of Ge quantum dots coherently embedded in an n-type Si (001) matrix. Evidence for an electron confinement in the vicinity of Ge dots was found. From the frequency-dependent measurements the electron binding energy was determined to be ~50 meV, which is consistent with the results of numerical analysis. The data are explained by a modification of the conduction band alignment induced by inhomogeneous tensile strain in Si around the buried Ge dots.

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Ultrafast Carrier Dynamics, Optical Amplification, and Lasing in Nanocrystal Quantum Dots

MRS Bulletin ◽

10.1557/mrs2001.256 ◽

2001 ◽

Vol 26 (12) ◽

pp. 998-1004 ◽

Cited By ~ 49

Author(s):

Victor I. Klimov ◽

Moungi G. Bawendi

Keyword(s):

Quantum Dots ◽

Quantum Wells ◽

Quantum Wires ◽

Electronic States ◽

Three Dimensions ◽

Band Edge ◽

Lasing Threshold ◽

Wide Energy Range ◽

Band Edge Emission ◽

Edge States

Semiconductor materials are widely used in both optically and electrically pumped lasers. The use of semiconductor quantum wells (QWs) as optical-gain media has resulted in important advances in laser technology. QWs have a two-dimensional, step-like density of electronic states that is nonzero at the band edge, enabling a higher concentration of carriers to contribute to the band-edge emission and leading to a reduced lasing threshold, improved temperature stability, and a narrower emission line. A further enhancement in the density of the band-edge states and an associated reduction in the lasing threshold are in principle possible using quantum wires and quantum dots (QDs), in which the confinement is in two and three dimensions, respectively. In very small dots, the spacing of the electronic states is much greater than the available thermal energy (strong confinement), inhibiting thermal depopulation of the lowest electronic states. This effect should result in a lasing threshold that is temperatureinsensitive at an excitation level of only 1 electron-hole (e-h) pair per dot on average. Additionally, QDs in the strongconfinement regime have an emission wavelength that is a pronounced function of size, adding the advantage of continuous spectral tunability over a wide energy range simply by changing the size of the dots.

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