On the drift mobility of a molecular polaron in the presence of Coulomb traps

We study the drift mobility of a molecular polaron in the presence of an external applied field and Coulomb traps. The model is based on one previously developed for geminate recombination of photogenerated charge carriers. It is shown that the unusual combination of Poole–Frenkel-like field dependence and non-Arrhenius temperature dependence of the mobility, measured experimentally in molecular films, is well reproduced by this model. Our key result is that this nearly universal experimental behavior of the mobility arises from competition between rates of polaron trapping and release from a very low density of Coulomb traps.

[1]  Donal D. C. Bradley,et al.  High brightness and efficiency blue light-emitting polymer diodes , 1998 .

[2]  E. Conwell,et al.  High-field hopping mobility in disordered molecular solids: A Monte Carlo study of off-diagonal disorder effects , 1994 .

[3]  W. E. Moerner,et al.  Polymeric Photorefractive Materials , 1994 .

[4]  L. B. Schein,et al.  Comparison of charge transport models in molecularly doped polymers , 1992 .

[5]  S. Rachovsky.  Theory of geminate recombination as a molecular process : the low-field regime , 1991 .

[6]  M. Abkowitz,et al.  Electronic transport in silicon backbone polymers , 1990 .

[7]  S. Rackovsky,et al.  Lattice Random Walk Theory of Geminate Recombination , 1989 .

[8]  S. Rackovsky,et al.  Electron trapping in double-stranded DNA: implications for formation of double-stranded breaks , 1989 .

[9]  L. Schein,et al.  Hole mobilities that decrease with increasing electric fields in a molecularly doped polymer , 1988 .

[10]  S. Rackovsky,et al.  Theory of geminate recombination on a lattice. IV. Results using large Coulomb radii on the simple cubic and square lattices , 1988 .

[11]  M. Abkowitz,et al.  Common features in the electronic transport behaviour of diverse glassy solids , 1988 .

[12]  D. Haarer,et al.  Transient photoconductivity of polysiloxane with pendant carbazole groups , 1988 .

[13]  Scher,et al.  Transition from dispersive to nondispersive transport: Photoconduction of polyvinylcarbarzole. , 1987, Physical review. B, Condensed matter.

[14]  S. Rackovsky,et al.  Effect of lattice topology on geminate recombination , 1985 .

[15]  S. Rackovsky,et al.  Theory of geminate recombination on a lattice , 1984 .

[16]  S. Rackovsky,et al.  Theory of geminate recombination as a molecular process , 1984 .

[17]  S. Rackovsky,et al.  Effect of neighboring charges and external fields on photosynthetic electron transfer , 1982 .

[18]  H. Scher,et al.  Chemical-rate treatment of small-polaron hopping between inequivalent sites , 1981 .

[19]  T. Holstein.  Reaction-rate treatment of small-polaron hopping the role of vibrational relaxation , 1978 .

[20]  T. Holstein.  Quantal occurrence-probability treatment of small-polaron hopping , 1978 .

[21]  D. Pai,et al.  Electric‐field‐enhanced conductivity in solids , 1975 .

[22]  E. Montroll,et al.  Anomalous transit-time dispersion in amorphous solids , 1975 .

[23]  W. D. Gill.  Drift mobilities in amorphous charge‐transfer complexes of trinitrofluorenone and poly‐n‐vinylcarbazole , 1972 .