scholarly journals Quantum Confinement of Electron–Phonon Coupling in Graphene Quantum Dots

2021 ◽  
Vol 12 (40) ◽  
pp. 9940-9946
Author(s):  
Marios Zacharias ◽  
Pantelis C. Kelires
Keyword(s):  
Quantum Dots ◽  
Quantum Confinement ◽  
Graphene Quantum Dots ◽  
Phonon Coupling ◽  
Electron Phonon Coupling

scholarly journals Ultra-broadband photodetectors based on epitaxial graphene quantum dots

Nanophotonics ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 735-740 ◽  
Author(s):  
Abdel El Fatimy ◽  
Anindya Nath ◽  
Byoung Don Kong ◽  
Anthony K. Boyd ◽  
Rachael L. Myers-Ward ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Quantum Confinement ◽  
Strong Dependence ◽  
Graphene Quantum Dots ◽  
Hot Electron ◽  
Phonon Coupling ◽  
Electron Phonon Coupling ◽  
Wide Range ◽  
Absorbed Power ◽  
Weak Electron

AbstractGraphene is an ideal material for hot-electron bolometers due to its low heat capacity and weak electron-phonon coupling. Nanostructuring graphene with quantum-dot constrictions yields detectors of electromagnetic radiation with extraordinarily high intrinsic responsivity, higher than 1×109 V W−1 at 3 K. The sensing mechanism is bolometric in nature: the quantum confinement gap causes a strong dependence of the electrical resistance on the electron temperature. Here, we show that this quantum confinement gap does not impose a limitation on the photon energy for light detection and these quantum-dot bolometers work in a very broad spectral range, from terahertz through telecom to ultraviolet radiation, with responsivity independent of wavelength. We also measure the power dependence of the response. Although the responsivity decreases with increasing power, it stays higher than 1×108 V W−1 in a wide range of absorbed power, from 1 pW to 0.4 nW.

PATH-INTEGRAL APPROACH FOR ELECTRON–PHONON INTERACTION EFFECTS IN HARMONIC QUANTUM DOTS

1996 ◽  
Vol 10 (22) ◽  
pp. 2781-2796 ◽  
Author(s):  
SOMA MUKHOPADHYAY ◽  
ASHOK CHATTERJEE
Keyword(s):  
Quantum Dots ◽  
Path Integral ◽  
State Energy ◽  
Coupling Parameter ◽  
Three Dimensions ◽  
Integral Approach ◽  
Phonon Coupling ◽  
Electron Phonon Interaction ◽  
Electron Phonon Coupling ◽  
Parabolic Confinement

We use the Feynman–Haken path-integral formalism to obtain the polaronic correction to the ground state energy of an electron in a polar semiconductor quantum dot with parabolic confinement in both two and three dimensions. We perform calculations for the entire range of the electron–phonon coupling parameter and for arbitrary confinement length. We apply our results to several semiconductor quantum dots and show that the polaronic effect in some of these dots can be considerably large if the dot sizes are made smaller than a few nanometers.

scholarly journals Graphene Quantum Dots as Flourishing Nanomaterials for Bio-Imaging, Therapy Development, and Micro-Supercapacitors

Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 866
Author(s):  
Merve Kortel ◽  
Bhargav D. Mansuriya ◽  
Nicole Vargas Santana ◽  
Zeynep Altintas
Keyword(s):  
Quantum Dots ◽  
Structural Properties ◽  
Edge Effects ◽  
Quantum Confinement ◽  
Review Paper ◽  
Graphene Quantum Dots ◽  
Heteroatom Doping ◽  
Size Dependent ◽  
Bio Imaging ◽  
Therapy Development

Graphene quantum dots (GQDs) are considerably a new member of the carbon family and shine amongst other members, thanks to their superior electrochemical, optical, and structural properties as well as biocompatibility features that enable us to engage them in various bioengineering purposes. Especially, the quantum confinement and edge effects are giving GQDs their tremendous character, while their heteroatom doping attributes enable us to specifically and meritoriously tune their prospective characteristics for innumerable operations. Considering the substantial role offered by GQDs in the area of biomedicine and nanoscience, through this review paper, we primarily focus on their applications in bio-imaging, micro-supercapacitors, as well as in therapy development. The size-dependent aspects, functionalization, and particular utilization of the GQDs are discussed in detail with respect to their distinct nano-bio-technological applications.

Low temperature photoluminescence properties of CsPbBr3 quantum dots embedded in glasses

2017 ◽  
Vol 19 (26) ◽  
pp. 17349-17355 ◽  
Author(s):  
Bing Ai ◽  
Chao Liu ◽  
Zhao Deng ◽  
Jing Wang ◽  
Jianjun Han ◽  
...  
Keyword(s):  
Activation Energy ◽  
Quantum Dots ◽  
Thermal Expansion ◽  
Low Temperature ◽  
Size Dependence ◽  
Phonon Coupling ◽  
Photoluminescence Properties ◽  
Electron Phonon Coupling ◽  
Cspbbr3 Quantum Dots ◽  
Low Temperature Photoluminescence

Size dependence of exciton activation energy, electron–phonon coupling strength, and thermal expansion of the bandgap of CsPbBr3 QDs were studied.

Strong electron-phonon coupling regime in self-assembled quantum dots

2004 ◽  
Vol 1 (6) ◽  
pp. 1391-1396 ◽  
Author(s):  
E. Deleporte ◽  
S. Hameau ◽  
J. N. Isaia ◽  
Y. Guldner ◽  
O. Verzelen ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Phonon Coupling ◽  
Strong Electron ◽  
Electron Phonon Coupling ◽  
Self Assembled

Size dependence of the electronic structures and electron-phonon coupling in ZnO quantum dots

2007 ◽  
Vol 91 (26) ◽  
pp. 262101 ◽  
Author(s):  
S. C. Ray ◽  
Y. Low ◽  
H. M. Tsai ◽  
C. W. Pao ◽  
J. W. Chiou ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Electronic Structures ◽  
Size Dependence ◽  
Phonon Coupling ◽  
Electron Phonon Coupling ◽  
Zno Quantum Dots

scholarly journals Recent progresses of quantum confinement in graphene quantum dots

2021 ◽  
Vol 17 (3) ◽  
Author(s):  
Si-Yu Li ◽  
Lin He
Keyword(s):  
Quantum Dots ◽  
Quantum Confinement ◽  
Bound States ◽  
Berry Phase ◽  
Graphene Quantum Dots ◽  
Bound State ◽  
Scanning Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Dirac Fermions ◽  
Tunneling Microscopy

AbstractGraphene quantum dots (GQDs) not only have potential applications on spin qubit, but also serve as essential platforms to study the fundamental properties of Dirac fermions, such as Klein tunneling and Berry phase. By now, the study of quantum confinement in GQDs still attract much attention in condensed matter physics. In this article, we review the experimental progresses on quantum confinement in GQDs mainly by using scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS). Here, the GQDs are divided into Klein GQDs, bound-state GQDs and edge-terminated GQDs according to their different confinement strength. Based on the realization of quasi-bound states in Klein GQDs, external perpendicular magnetic field is utilized as a manipulation approach to trigger and control the novel properties by tuning Berry phase and electron-electron (e-e) interaction. The tip-induced edge-free GQDs can serve as an intuitive mean to explore the broken symmetry states at nanoscale and single-electron accuracy, which are expected to be used in studying physical properties of different two-dimensional materials. Moreover, high-spin magnetic ground states are successfully introduced in edge-terminated GQDs by designing and synthesizing triangulene zigzag nanographenes.

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