Molecularly doped polymer excitation

A triplet exciton annihilation mechanism has been proposed for charge generation in molecularly doped polymers initiated with very fast, high-intensity, excitation [25b,c]. In this mechanism it is proposed that both charge separation, associated with the Onsager model, and the fusion process are very strongly field-dependent. This model has not been invoked in recent years. 

This paper is devoted to the presentation of a brief overview of a recently-developed "relaxation-localization" model of localized molecular-ion and exciton states in polymers and molecular glasses. This model was proposed initially to interpret photoemission measurements from two pgn ant-group polymers polystyrene and p ly(2-vinyl pyridine.) It ext was utilized in the prediction and subsequent observation of surface states of molecular solids as well as of the temperature dependence of photoe iss on and UV absorption linewidths of molecular films. Having proven successful in describing the spectroscopic properties of typical pendant-group polymers and molecular glasses, the model most recently has been extended to provide a description of electron-transfer processes in both these materials and molecularly-doped polymers. Therefore it affords a unified and experimentally-verified microscopic description of electron ionization, excitation and transfer processes in a variety of molecular and polymeric materials. 

Quantum well interface roughness Carrier or doping density Electron temperature Rotational relaxation times Viscosity Relative quantity Molecular weight Polymer conformation Radiative efficiency Surface damage Excited state lifetime Impurity or defect concentration... 

Ringsdorf and co-workers have shown that triphenylenes can form alternating donor—acceptor supramolecular polymers in solution by doping them with equimolar amounts of electron acceptors.128129 Supramolecular polymers formed in this manner allow for electron transfer perpendicular to the molecular planes upon excitation of the chromophores, i.e., unidirectional charge-transport through the column. 130 The formation of these donor—acceptor pairs is favored in apolar solvents. In more polar solvents the triphenylenes alone do not polymerize and consequently donor—acceptor polymers with low DP are formed. 

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