Fractal microstructures of light-emitting porous silicon films

Correlation of excitation-wavelength dependent photoluminescence with the fractal microstructures of porous silicon

“…The fractal microstructures can give a solution to the size distribution problem in porous silicon film. In literature, the fractal microstructures were reported for the entire network of porous silicon [14][15][16][17][24][25][26][27]. Diffusion-limited aggregation is the process in which randomly walking particles come together to form aggregates and networks [28], and it has become one of the most important models of fractal growth [29].…”

“…Furthermore, Wesolowski proposed that the fractal microstructures of porous silicon are responsible for the existence of a size distribution in porous silicon [12]. Indeed, recent studies on the microstructures of porous silicon showed that the network of a porous silicon film exhibits the characteristics of fractals [14][15][16][17]. Therefore, we surmise that the fractal microstructures of porous silicon will produce significant effect on its photoluminescence if quantum confinement effect is valid for the silicon www.elsevier.com/locate/apsusc Available online at www.sciencedirect.com nanocrystallites.…”

Enhanced crystallization on porous silicon: Facts and models

“…where n is the density of adsorbed molecules on a flat surface; D the fractal dimension: 2.2 rD r2.6-found for porous silicon [5][6][7][8]19]; L c the correlation length or upper scale of self-similarity. The local supersaturation existing near a porous silicon surface due to its fractality allowed nucleation and crystallization to occur under conditions, which are insufficient for spontaneous nucleation on smooth surfaces or on surfaces with regular pores [12,17,18].…”

Compositional evolution and surface-related phenomena effects in ZnS–SiO2 nanocomposite films

“…The fractal dimension is a measure of the irregularity of the boundary of the object, and box-counting method is often employed to calculate the fractal dimension [46]. Fractal dimension, D f , is defined as [47]:…”