Abstract
We present Monte Carlo simulation results for time-independent drift and spatial spreading of a packet of charge carriers executing a random walk within a manifold of hopping sites under a bias field. The shape of the density-of-states profile is assumed to be Gaussian (width a). The ratio eD/μkT, equal to unity for ordinary diffusion, is found to increase dramatically with increasing disorder and bias field. For σ/kT= 3.5 and fields of order 106Vcm-1, eD/μkT reaches values of order 103. The effect accounts for the anomalous spreading of time-of-flight profiles often seen in photocarrier transit time studies on various polymeric systems. The role of disorder in charge-carrier transport is emphasized.
Original language | English (US) |
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Pages (from-to) | 587-601 |
Number of pages | 15 |
Journal | Philosophical Magazine B: Physics of Condensed Matter; Statistical Mechanics, Electronic, Optical and Magnetic Properties |
Volume | 63 |
Issue number | 3 |
DOIs | |
State | Published - Mar 1991 |
Externally published | Yes |
ASJC Scopus subject areas
- Chemical Engineering(all)
- Physics and Astronomy(all)