The Concentration Dependence of the Hole Mobility of a Hydrazone Doped Polymer

Abstract

Hole mobilities of 4-diethylaminobenzaldehyde diphenylhydrazone (HDZ-F) doped poly(styrene) have been measured over a wide concentration range. The results have been described by a formalism based on disorder. The formalism is premised on the argument that charge transport occurs by hopping through a manifold of localized states that are distributed in energy and distance. The key parameter of the formalism is σ, the energy with of the hopping site manifold. For HDZ-F doped PS, σ is concentration-dependent. The maximum value is 0.121 eV and occurs at approximately 15% HDZ-F. The width decreases sharply for concentrations above and below. The concentration dependence is described by a model of dipolr disorder. The model is based on the assumption that the total widths are comprised of a dipolar component and a van der Waals component. The interpretation of the experimental results leads to the conclusion that the concentration dependence of the total width is largely determined by the van der Waals component.

Hole transport in polystyrene and polycarbonate doped with polar dopants

“…Parameter W is likewise small: 0.40. This is confirmed also by the fact that a good descrip tion of the experimental curves can be achieved with out correction for the Poole-Frenkel effect; however, with an increase in the field intensity from 0 to 10 V/μm, hole mobility increases by a factor of almost 4 [18].…”

Hopping Charge Transport in Disordered Organic Materials: Where Is the Disorder?

“…In future we will use notations σ S for the rms disorder, calculated from S(T ), and σ T for the corresponding rms disorder, calculated from the temperature dependence of µ(E → 0). Figure 2: Dependence of σ on the concentration of polar constituents [18,16]: σ S (empty symbols) and σ T (filled symbols), correspondingly. Squares correspond to the system DEH:PS [18], circles correspond to the system with copolymer PS-BA as a binder [16], and lines are shown as a guide for an eye.…”

“…Information we needed is pretty rare in literature and we found only four papers where the data for S(T ) have been provided for different concentrations of polar constituents [16,18,20,19]. Fortunately, these papers describe very different situations.…”

The role played by a polymer matrix in the transfer of charge carriers in molecularly doped polumers

“…Molecularly doped polymers were prepared at the Eastman Kodak Company (USA) using technology accepted there [1,9]. Polymer layers were deposited on a PET substrate 180 μm thick with a sputtered Ni layer.…”