China
Africa
Explore chapters and articles related to this topic
Silicon nanoparticles via pulsed laser ablation in liquid
Published in Klaus D. Sattler, Silicon Nanomaterials Sourcebook, 2017
The quantum confinement effect clearly manifests itself in the absorption properties of the PLAL-produced SiNP colloids. The band gap is markedly blue shifted compared to bulk silicon (1.1 eV) resulting in an almost colorless colloid absorbing in the near UV. This is common to almost all reported experiments and demonstrates the presence of small (<10 nm) and ultrasmall (<5 nm) silicon quantum dots which can be in the form of isolated nanocrystals, aggregated polynanocrystals, or embedded in a silicon oxide matrix.
Photoinduced relaxation dynamics of nitrogen-capped silicon nanoclusters: a TD-DFT study
Published in Molecular Physics, 2018
Xiang-Yang Liu, Xiao-Ying Xie, Wei-Hai Fang, Ganglong Cui
Silicon quantum dots are of great interest for applications in biomedicine, electronics, optoelectronics, nonlinear optics, and solar energy [1–9]. One of the major objectives of silicon-based optoelectronics is developing silicon quantum dots with optically or electrically controllable luminescence properties. The luminescence of silicon quantum dots is attributed to the radiative recombination of carriers and the wavelengths in the visible range can be tuned by adjusting the size of silicon quantum dots [10,11]. However, the luminescence quantum yield of free-standing silicon quantum dots is limited because defect structures may efficiently capture the carriers and provide many nonradiative recombination centres for electron-hole pairs. In order to inhibit these radiationless processes and increase luminescence quantum yields, silicon quantum dot surfaces are needed to be modified, for example, by saturating all dangling bonds, removing defect structures, or coupling with electronically active chromophores [12,13]. This treatment always leads to short-lived excited-states and high photoluminescent quantum yields.