A study on the diffusion of oxygen into C60 molecular crystals
| Autor: | Chih-Ming Yang, 楊志明 |
|---|---|
| Rok vydání: | 2003 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 91 The interaction of oxygen with C60 molecular crystal causes it’s dark conductivity to increase remarkably. The details of the diffusion mechanism are studied by measuring the decay of dark current of the C60 molecular crystals after exposing to air at four different temperatures with four different crystals grown by the same conditions. From the curre fitting of the decay of dark conductivity, two decay time constants and are obtained, where is corresponding to the decay of carrier concentration and is corresponding to the descry of carrier mobility. From the values of, the corresponding D(T) can be estimated; and from the Arrhenius plot, the values of activation energy Ea1=1.1±0.1eV and Ea2=0.7±0.1eV are obtained. The physical meaning of these two values are discussed. Finally, from the temperature dependence of dark conductivity before exposing to air, the activation energy of the trapping center in C60 molecular crystal is estimated and discussed. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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