TY - JOUR

T1 - Fundamental characteristic length scale for the field dependence of hopping charge transport in disordered organic semiconductors

AU - Nenashev, A. V.

AU - Oelerich, J. O.

AU - Dvurechenskii, A. V.

AU - Gebhard, F.

AU - Baranovskii, S. D.

PY - 2017/7/21

Y1 - 2017/7/21

N2 - Using analytical arguments and computer simulations, we show that the dependence of the hopping carrier mobility on the electric field μ(F)/μ(0) in a system of random sites is determined by the localization length a, and not by the concentration of sites N. This result is in drastic contrast to what is usually assumed in the literature for a theoretical description of experimental data and for device modeling, where N-1/3 is considered as the decisive length scale for μ(F). We show that although the limiting value μ(F→0) is determined by the ratio N-1/3/a, the dependence μ(F)/μ(0) is sensitive to the magnitude of a, and not to N-1/3. Furthermore, our numerical and analytical results prove that the effective temperature responsible for the combined effect of the electric field F and the real temperature T on the hopping transport via spatially random sites can contain the electric field only in the combination eFa.

AB - Using analytical arguments and computer simulations, we show that the dependence of the hopping carrier mobility on the electric field μ(F)/μ(0) in a system of random sites is determined by the localization length a, and not by the concentration of sites N. This result is in drastic contrast to what is usually assumed in the literature for a theoretical description of experimental data and for device modeling, where N-1/3 is considered as the decisive length scale for μ(F). We show that although the limiting value μ(F→0) is determined by the ratio N-1/3/a, the dependence μ(F)/μ(0) is sensitive to the magnitude of a, and not to N-1/3. Furthermore, our numerical and analytical results prove that the effective temperature responsible for the combined effect of the electric field F and the real temperature T on the hopping transport via spatially random sites can contain the electric field only in the combination eFa.

KW - CARRIER TRANSPORT

KW - EFFECTIVE TEMPERATURE

KW - DOPED POLYMERS

KW - BAND TAILS

KW - SOLIDS

KW - RECOMBINATION

KW - ELECTRONS

UR - http://www.scopus.com/inward/record.url?scp=85026486561&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.96.035204

DO - 10.1103/PhysRevB.96.035204

M3 - Article

AN - SCOPUS:85026486561

VL - 96

JO - Physical Review B

JF - Physical Review B

SN - 2469-9950

IS - 3

M1 - 035204

ER -