The role of group dipole moments on electron transport in vapor deposited acceptor glasses

Autor: Paul M. Borsenberger, M. B. O'Regan, W. T. Gruenbaum
Rok vydání: 1995
Předmět:
Zdroj: Physica Status Solidi (a). 148:259-266
ISSN: 1521-396X
0031-8965
DOI: 10.1002/pssa.2211480122
Popis: Electron mobilities are measured in vapor deposited films of 3,5-dimethyl-3',5'-diisopropyl-4,4'-diphenoquinone (DPQ) over a range of fields and temperatures. The results are described by a transport formalism based on disorder, due to Bassler and coworkers. The formalism is premized on the assumption that charge propagation occurs by hopping through an array of localized states with superimposed energetic and positional disorder. The key parameters of the formalism are , the energy width of the hopping site manifold, Σ, a parameter that describes the degree of positional disorder, and μ 0 , a prefactor mobility. For DPQ, = 0.112 eV, Σ = 1.7, and μ 0 = 7.6 × 10 −4 cm 2 /V s. The width of the hopping site manifold can be described by a model based on dipolar disorder, if it is assumed that the dipole moments that determine the width are moments associated with the carbonyl groups. The degree of positional disorder is attributed to packing constraints. The prefactor mobility, in conjunction with literature values for a wide range of vapor deposited molecular glasses, suggests that the prefactor is dependent on dipole moment, decreasing with increasing dipole moment
Databáze: OpenAIRE
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