Charge carrier energy disorder in polar amorphous organic thin films

Publication Type:

Journal Article

Source:

Phys. Rev. Lett., APS, Volume 97, Issue 21, p.216402 (2006)

ISBN:

0031-9007

Keywords:

2006, 2013 and earlier

Abstract:

We report Monte Carlo calculations of the charge carrier energy level disorder in polar amorphous organic solids arising from electrostatic
interactions between polarizable molecular charge distributions. In
contrast with previous reports in which the discrete molecular
polarizibilities are modeled as a dielectric continuum having dielectric
constant epsilon, our calculations take account of the molecular-scale
polarization inhomogeneity. We find that the previously reported 1/epsilon
scaling rule underestimates the charge carrier energy level disorder by
more than a factor of 2 for typical values of epsilon. Such an
underestimation strongly impacts the analysis of charge carrier transport
in polar amorphous organic thin films, due to the strong dependence of the
charge carrier mobility on the energy disorder.