Hole transport in triphenylmethane doped polymers

• Published in: Japanese Journal of Applied Physics 1996-05, Vol.35 (5A), p.2704-2708
• Main Authors: GRUENBAUM, W. T, MAGIN, E. H, BORSENBERGER, P. M
• Format: Article
• Language: English
• Subjects: Applied sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Conductivity of specific materials; Electrical, magnetic and optical properties; Electronic transport in condensed matter; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Physics; Polymers; organic compounds (including organic semiconductors); Properties and characterization
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.35.2704

Hole mobilities have been measured in poly(styrene) (PS) doped with a series of triphenylmethane (TPM) derivatives with different dipole moments. The results are described by a formalism based on disorder, due to Bässler and coworkers. The formalism is premised on the assumption that charge transport occurs by hopping through a manifold of localized states that are distributed in energy. A key parameter of the formalism is the energy width of the hopping site manifold. For TPM doped PS, the widths are between 0.106 and 0.117 eV, increasing with increasing dipole moment. The widths are described by a model based on dipolar disorder. The model is based on the assumption that the total width is comprised of a dipolar component and a van der Waals component. For TPM doped PS, the dipolar components are between 0.021 and 0.052 eV, while the van der Waals components are 0.105 eV. The van der Waals components are significantly larger than for PS doped with a wide range of triarylamine (TAA) molecules. The difference in the van der Waals component is described by a charge delocalization argument and is the principal reason for the difference in mobility of TPM and TAA doped polymers.