Morphology of porous silicon structures formed by anodization of heavily and lightly doped silicon

Fractal microstructures of light-emitting porous silicon films

“…2 suggest that the microstructures of the 23-mm-thick PS film be fractals. At this point, our results agree with the simulated results in literature [13][14][15][16][17]. As the magnification increases from 1000 in Fig.…”

“…From electron microscopy 4data, it was concluded that the sizes of individual silicon crystallites in PS films were in the order of nanometers [5][6][7][8]. When the whole PS network was taken into consideration, recent studies demonstrated that the microstructures of the whole PS network exhibit fractal features [9][10][11][12][13][14][15][16][17]. On one hand, the fractal features of the microstructures of a PS network were supported by experiments such as the ac conductivity in a low-frequency regime [9], the photoluminescence spectroscopy [10,11], the hydrogen concentration measurements [12], and the atomic force microscopy [13], respectively.…”

“…On one hand, the fractal features of the microstructures of a PS network were supported by experiments such as the ac conductivity in a low-frequency regime [9], the photoluminescence spectroscopy [10,11], the hydrogen concentration measurements [12], and the atomic force microscopy [13], respectively. On the other hand, computer simulation on PS formation was performed by Aleksandrov and Novikov [14] while fractal models on the pore formation in PS films were proposed by Aroutiounian et al [15] and by Makushok et al [16], respectively. All these studies showed that the microstructures of the whole PS network are characteristic of fractals [13][14][15][16][17].…”

“…On the other hand, computer simulation on PS formation was performed by Aleksandrov and Novikov [14] while fractal models on the pore formation in PS films were proposed by Aroutiounian et al [15] and by Makushok et al [16], respectively. All these studies showed that the microstructures of the whole PS network are characteristic of fractals [13][14][15][16][17]. Because the fractal microstructures of a PS network could pose significant effects on its physical properties [9,10], it would be important to perform a detailed investigation on the microstructures of a whole PS network.…”

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].…”