A fractal process of hydrogen diffusion in a-Si: H with exponential energy distribution

作者：Hikita Harumi^*; Ishikawa Hirohisa; Morigaki Kazuo

来源：International Journal of Modern Physics B, 2017, 31(9): 1750060.

DOI：10.1142/S0217979217500606

• Fractal
• fractal dimension
• anomalous diffusion
• thermal diffusion of hydrogen
• a-Si:H
• exponential distribution of the states in energy

Hydrogen diffusion in a-Si:H with exponential distribution of the states in energy exhibits the fractal structure. It is shown that a probability P(t) of the pausing time t has a form of t(alpha) (alpha: fractal dimension). It is shown that the fractal dimension alpha = T-r/T-0 (T-r: hydrogen temperature, T-0: a temperature corresponding to the width of exponential distribution of the states in energy) is in agreement with the Hausdorff dimension. A fractal graph for the case of alpha <= 1 is like the Cantor set. A fractal graph for the case of alpha > 1 is like the Koch curves. At alpha - infinity, hydrogen migration exhibits Brownian motion. Hydrogen diffusion in a-Si:H should be the fractal process.

• 出版日期2017-4-10