| 초록 |
Organic pi-conjugated materials are promising active elements in optoelectronic devices such as field-effect transistors (FET), light-emitting diodes (LED), or photovoltaic and solar cells. In particular, oligoacenes and their derivatives have attracted much attention in recent years due to their high current mobilities. The performance of these molecular devices depends highly on the efficiency of the charge-transfer processes. The main parameters impacting on charge-transport are transfer integrals between adjacent oligomer or polymer chains in the solid state and reorganization energies due to the hole-phonon or electron-phonon interactions. Here, quantum-mechanical methods are applied in order to characterize the nature of charge transport in oligoacenes and their derivatives. Calculated reorganization energies indicate that hole-transfer is more favorable than electron transfer in those organic semiconductors. It is also shown that the magnitude of transfer integrals is extremely sensitive to the type of the molecular packing in the sold state. Thus, this qualitative interpretation of charge-transport nature in organic semiconductors is crucial to understand for the rational design of new organic semiconducting materials. |
