Electron–Hole Confinement Symmetry in Silicon Quantum Dots

Nano Letters ◽  
2015 ◽  
Vol 15 (8) ◽  
pp. 5336-5341 ◽  
Author(s):  
Filipp Mueller ◽  
Georgios Konstantaras ◽  
Paul C. Spruijtenburg ◽  
Wilfred G. van der Wiel ◽  
Floris A. Zwanenburg
2004 ◽  
Vol 46 (1) ◽  
pp. 27-31 ◽  
Author(s):  
V. A. Belyakov ◽  
V. A. Burdov ◽  
D. M. Gaponova ◽  
A. N. Mikhaylov ◽  
D. I. Tetelbaum ◽  
...  

1999 ◽  
Vol 571 ◽  
Author(s):  
R.K. Soni ◽  
L.F. Fonseca ◽  
O. Resto ◽  
S.Z. Weisz ◽  
S. Tripathy

ABSTRACTWe have carried out a resonance Raman study of line-shape in silicon quantum dots synthesized on a quartz substrate by co-sputtering bulk Si and Si02. Optical transmission measurements are used to evaluate dot size distribution. The size distribution shows peaks around 1.0 and 1.4 nm. The Si dots exhibit photoluminescence in the visible region, which shifts to higher energy with decreasing size. The size dependence of Raman scattering shows phonon softening and increasing asymmetrical broadening for small dots (< 2nm). The observed spectra are compared with calculations considering electron-hole interactions at a quasi-direct gap of a spherical quantum dot.


Author(s):  
M.J. Kim ◽  
L.C. Liu ◽  
S.H. Risbud ◽  
R.W. Carpenter

When the size of a semiconductor is reduced by an appropriate materials processing technique to a dimension less than about twice the radius of an exciton in the bulk crystal, the band like structure of the semiconductor gives way to discrete molecular orbital electronic states. Clusters of semiconductors in a size regime lower than 2R {where R is the exciton Bohr radius; e.g. 3 nm for CdS and 7.3 nm for CdTe) are called Quantum Dots (QD) because they confine optically excited electron- hole pairs (excitons) in all three spatial dimensions. Structures based on QD are of great interest because of fast response times and non-linearity in optical switching applications.In this paper we report the first HREM analysis of the size and structure of CdTe and CdS QD formed by precipitation from a modified borosilicate glass matrix. The glass melts were quenched by pouring on brass plates, and then annealed to relieve internal stresses. QD precipitate particles were formed during subsequent "striking" heat treatments above the glass crystallization temperature, which was determined by differential thermal analysis.


2018 ◽  
Author(s):  
Oscar A. Douglas-Gallardo ◽  
Cristián Gabriel Sánchez ◽  
Esteban Vöhringer-Martinez

<div> <div> <div> <p>Nowadays, the search of efficient methods able to reduce the high atmospheric carbon dioxide concentration has turned into a very dynamic research area. Several environmental problems have been closely associated with the high atmospheric level of this greenhouse gas. Here, a novel system based on the use of surface-functionalized silicon quantum dots (sf -SiQDs) is theoretically proposed as a versatile device to bind carbon dioxide. Within this approach, carbon dioxide trapping is modulated by a photoinduced charge redistribution between the capping molecule and the silicon quantum dots (SiQDs). Chemical and electronic properties of the proposed SiQDs have been studied with Density Functional Theory (DFT) and Density Functional Tight-Binding (DFTB) approach along with a Time-Dependent model based on the DFTB (TD-DFTB) framework. To the best of our knowledge, this is the first report that proposes and explores the potential application of a versatile and friendly device based on the use of sf -SiQDs for photochemically activated carbon dioxide fixation. </p> </div> </div> </div>


2021 ◽  
Vol 125 (6) ◽  
pp. 3421-3431
Author(s):  
İrem Nur Gamze Özbilgin ◽  
Batu Ghosh ◽  
Hiroyuki Yamada ◽  
Naoto Shirahata

2021 ◽  
pp. 2100288
Author(s):  
Marc Julian Kloberg ◽  
Haoyang Yu ◽  
Elisabeth Groß ◽  
Felix Eckmann ◽  
Tassilo M. F. Restle ◽  
...  

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