TY - JOUR

T1 - Percolative transport in amorphous semiconductors

AU - Halpern, V.

PY - 1987/12

Y1 - 1987/12

N2 - For phonon-assisted transport between localized electronic states in amorphous semiconductors, the conductance of the medium is known to be the same as that of an equivalent resistor network. If the impedances of the resistors between adjacent sites vary over several orders of magnitude, this conductance is determined mainly by the magnitude of the critical impedance Zc such that a percolation path through the system of resistors with impedance less than Z0 exists only if Z0≥Zc. The calculation of Zc is complicated by the dependence of the impedance between a pair of sites on the energies of the states localized around them. Various methods for calculating Zc, and its dependence on the parameters of the system, are compared for a model system in which all the states have one of two discrete energies. Our main conclusion is that, in the calculation of Zc from the mean number of bonds per site, it can be very important to optimize the range of sites and bonds that are considered.

AB - For phonon-assisted transport between localized electronic states in amorphous semiconductors, the conductance of the medium is known to be the same as that of an equivalent resistor network. If the impedances of the resistors between adjacent sites vary over several orders of magnitude, this conductance is determined mainly by the magnitude of the critical impedance Zc such that a percolation path through the system of resistors with impedance less than Z0 exists only if Z0≥Zc. The calculation of Zc is complicated by the dependence of the impedance between a pair of sites on the energies of the states localized around them. Various methods for calculating Zc, and its dependence on the parameters of the system, are compared for a model system in which all the states have one of two discrete energies. Our main conclusion is that, in the calculation of Zc from the mean number of bonds per site, it can be very important to optimize the range of sites and bonds that are considered.

UR - http://www.scopus.com/inward/record.url?scp=0023595853&partnerID=8YFLogxK

U2 - 10.1080/13642818708215320

DO - 10.1080/13642818708215320

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AN - SCOPUS:0023595853

SN - 1364-2812

VL - 56

SP - 861

EP - 871

JO - Philosophical Magazine B: Physics of Condensed Matter; Statistical Mechanics, Electronic, Optical and Magnetic Properties

JF - Philosophical Magazine B: Physics of Condensed Matter; Statistical Mechanics, Electronic, Optical and Magnetic Properties

IS - 6

ER -