scholarly journals Corrections to the Capacitance between Two Electrodes Due to the Presence of Quantum Confined System

VLSI Design ◽  
1998 ◽  
Vol 6 (1-4) ◽  
pp. 345-349 ◽  
Author(s):  
M. Macucci ◽  
K. Hess
Keyword(s):  
Quantum Dots ◽  
Free Energy ◽  
Applied Voltage ◽  
Differential Capacitance ◽  
Quantum Capacitance ◽  
Parallel Plates ◽  
Random Size ◽  
Quantum Confined ◽  
Special Case ◽  
Confined System

We have studied the capacitance between two parallel plates enclosing a quantum confined system and its dependence on the applied voltage. The concepts of capacitance and differential capacitance are discussed together with their applicability to systems characterized by single.electron tunneling. We determine the tunneling thresholds by means of a formalism based on the minimization of the system free energy and we retrieve, as a special case, Luryi's quantum capacitance formula. We apply our method to the study of an idealized system made up of a number of quantum dots with random size distributed according to a gaussian. Results are shown for different choices of the position of the dots between the plates and of the voltage span applied to perform the measurement of the differential capacitance.

Free energy and kinetics of cAMP permeation through connexin26 via applied voltage and milestoning

2021 ◽  
Author(s):  
Wenjuan Jiang ◽  
Yi-Chun Lin ◽  
Wesley Botello-Smith ◽  
Jorge Contreras ◽  
Andrew L. Harris ◽  
...  
Keyword(s):  
Free Energy ◽  
Applied Voltage ◽  
Kinetics Of

OPTICAL PROPERTIES OF CdTe AND CdS QUANTUM DOTS IN GLASS

1992 ◽  
Vol 01 (01) ◽  
pp. 25-50 ◽  
Author(s):  
V. ESCH ◽  
K. KANG ◽  
B. FLUEGEL ◽  
Y.Z. HU ◽  
G. KHITROVA ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Optical Nonlinearities ◽  
Cds Quantum Dots ◽  
Temperature Dependent ◽  
Linear Absorption ◽  
Crystallite Sizes ◽  
Band Mixing ◽  
Quantum Confined ◽  
Coulomb Effects

We summarize the linear and nonlinear optical properties of a variety of CdTe and CdS quantum dots in glass. The measured linear absorption of the CdTe sample is compared with calculations involving valence-band mixing due to the quantum confinement. The temperature dependence of the lowest quantum-confined transition and its linewidth for samples with various crystallite sizes are measured and compared with a simple model. It is found that the shift of the energetically lowest quantum-confined transition as a function of temperature is the same as the temperature-dependent band-gap reduction in bulk materials. Excitation of the sample with pulses ranging from femtoseconds to microseconds allows distinguishing between various mechanisms responsible for the observed optical nonlinearities. At very early times, phase-space filling and Coulomb interaction between the excited charged carriers are responsible for the absorption changes. At later times, Coulomb effects due to “trapped” carriers remain and last for nanoseconds or microseconds.

Quantum-confined Franz-Keldysh effect in CdTe quantum dots in glass

Optics News ◽  
1989 ◽  
Vol 15 (12) ◽  
pp. 26 ◽  
Author(s):  
V. Esch ◽  
G. Khitrova ◽  
H. M. Gibbs ◽  
Xu Jiajin ◽  
L. C. Liu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Cdte Quantum Dots ◽  
Quantum Confined ◽  
Franz Keldysh Effect

scholarly journals Manipulating quantum-confined Stark shift in electroluminescence from quantum dots with side gates

2008 ◽  
Vol 10 (5) ◽  
pp. 053036 ◽  
Author(s):  
Xiulai Xu ◽  
Aleksey Andreev ◽  
David A Williams
Keyword(s):  
Quantum Dots ◽  
Stark Shift ◽  
Quantum Confined

Solution NMR Spectroscopy as a Useful Tool to Investigate Colloidal Nanocrystal Dispersions from the Capping Ligand's Point of View

2006 ◽  
Vol 984 ◽  
Author(s):  
Jose C Martins ◽  
Jose C Martins ◽  
Iwan Moreels ◽  
Zeger Hens
Keyword(s):  
Quantum Dots ◽  
Free Energy ◽  
Field Gradient ◽  
Dynamic Equilibrium ◽  
Semiconductor Nanocrystals ◽  
Point Of View ◽  
Solution Nmr ◽  
Free Energy Of Adsorption ◽  
Ligand Interaction ◽  
Pulsed Field

AbstractColloidal semiconductor nanocrystals or quantum dots are an important building block in bottom-up nanotechnology. They consist of an inorganic, crystalline core surrounded by a monolayer of organic ligands. As these ligands can be modified or exchanged for others, they provide a convenient way to give the quantum dots functionality. Here, we show that solution NMR techniques, including diffusion pulsed field gradient spectroscopy, is a very useful tool to investigate the ligands of colloidal nanocrystals. This is demonstrated using InP quantum dots with trioctylphospine oxide ligands as an example. Combining 1H-13C HSQC spectroscopy with pulsed field gradient diffusion NMR, an unequivocal identification of the resonances of the bound ligands is possible. This leads to the determination of the diffusion coefficient of the nanocrystals in solution and allows to verify capping exchange procedures. By calibrating the surface area of the NMR resonances using a solute of known concentration, the density of ligands at the nanocrystal surface can be quantified. We could demonstrate that a dynamic equilibrium exists between bound and free ligands. Analysis of the corresponding adsorption isotherm - determined using 1H NMR - leads to an estimation of the free energy of adsorption and the free energy of ligand-ligand interaction at the nanocrystals surface. Similar investigations are in progress on capped PbSe and ZnO2 nanoparticles. Preliminary results strongly support the generic nature of the approach described for the case of TOPO capped InP nanocrystals.

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