Dynamical Percolation Model of Conductance Fluctuations in Hydrogenated Amorphous Silicon

Conductance fluctuations in hydrogenated amorphous silicon ( $a$-Si:H) are simulated using a dynamical model of resistor diffusion on a lattice held at the percolation threshold. A fraction of lattice sites is designated as a trap, such that when a resistor diffuses onto that site it remains localized for a finite period of time. When a distribution of traps based on the defect density of $a$-Si:H is employed, the conductance fluctuations of the resistor network exhibit $1/f$ noise interspersed with random telegraph switching noise, as observed in experimental measurements of $a$-Si:H.