scholarly journals Luminescence mechanism in hydrogenated silicon quantum dots with a single oxygen ligand

2021 ◽  
Vol 3 (8) ◽  
pp. 2245-2251
Author(s):  
Hong Shen ◽  
Zhiyuan Yu ◽  
Jinjin Wang ◽  
Ming Lu ◽  
Chong Qiao ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Radiative Transition ◽  
Silicon Quantum Dots ◽  
Hydrogenated Silicon ◽  
Oxygen Ligand ◽  
Single Oxygen

Upon excitation, electrons are strongly localized near the SiO site, which induces a faster radiative transition.

scholarly journals Electronic and Optical Properties of Small Hydrogenated Silicon Quantum Dots Using Time-Dependent Density Functional Theory

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Muhammad Mus-’ab Anas ◽  
Geri Gopir
Keyword(s):  
Density Functional Theory ◽  
Quantum Dots ◽  
Absorption Spectrum ◽  
Density Functional ◽  
Time Dependent ◽  
Silicon Quantum Dots ◽  
Functional Theory ◽  
Hydrogenated Silicon ◽  
Small Quantum ◽  
Dependent Density

This paper presents a systematic study of the absorption spectrum of various sizes of small hydrogenated silicon quantum dots of quasi-spherical symmetry using the time-dependent density functional theory (TDDFT). In this study, real-time and real-space implementation of TDDFT involving full propagation of the time-dependent Kohn-Sham equations were used. The experimental results for SiH4and Si5H12showed good agreement with other earlier calculations and experimental data. Then these calculations were extended to study larger hydrogenated silicon quantum dots with diameter up to 1.6 nm. It was found that, for small quantum dots, the absorption spectrum is atomic-like while, for relatively larger (1.6 nm) structure, it shows bulk-like behavior with continuous plateau with noticeable peak. This paper also studied the absorption coefficient of silicon quantum dots as a function of their size. Precisely, the dependence of dot size on the absorption threshold is elucidated. It was found that the silicon quantum dots exhibit direct transition of electron from HOMO to LUMO states; hence this theoretical contribution can be very valuable in discerning the microscopic processes for the future realization of optoelectronic devices.

Communication: Photoinduced Carbon Dioxide Binding with Surface-Functionalized Silicon Quantum Dots

2018 ◽  
Author(s):  
Oscar A. Douglas-Gallardo ◽  
Cristián Gabriel Sánchez ◽  
Esteban Vöhringer-Martinez
Keyword(s):  
Carbon Dioxide ◽  
Quantum Dots ◽  
Atmospheric Carbon Dioxide ◽  
Density Functional ◽  
Tight Binding ◽  
Carbon Dioxide Concentration ◽  
Research Area ◽  
Silicon Quantum Dots ◽  
Dependent Model ◽  
Photoinduced Charge

<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>

Size-Dependent Photothermal Performance of Silicon Quantum Dots

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

scholarly journals Surface‐Anisotropic Janus Silicon Quantum Dots via Masking on 2D Silicon Nanosheets

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

Annealing and excitation dependent photoluminescence of silicon rich silicon nitride films with silicon quantum dots

Vacuum ◽  
2015 ◽  
Vol 121 ◽  
pp. 147-151 ◽  
Author(s):  
Wugang Liao ◽  
Xiangbin Zeng ◽  
Xixing Wen ◽  
Xiaoxiao Chen ◽  
Wenzhao Wang
Keyword(s):  
Quantum Dots ◽  
Silicon Nitride ◽  
Silicon Quantum Dots ◽  
Silicon Nitride Films
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