TY - JOUR
T1 - Anomalous time-independent diffusion of charge carriers in a random potential under a bias field
AU - Pautmeier, L.
AU - Richert, R.
AU - Bässler, H.
N1 - Funding Information:
We are indebted to M. Abkowitz for stimulating discussions. Financial support by the Deutsche Forschungsgemeinschaft and the Fonds der Chemischen Industrie is gratefully acknowledged.
PY - 1991/3
Y1 - 1991/3
N2 - 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.
AB - 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.
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U2 - 10.1080/13642819108225974
DO - 10.1080/13642819108225974
M3 - Article
AN - SCOPUS:0026121973
VL - 63
SP - 587
EP - 601
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
SN - 1364-2812
IS - 3
ER -