Relationship between Electric Potential Distribution and Trap Depth in Polymeric Materials

The relationship between a three dimensional electric potential distribution and electron trap depth in polymeric material was discussed. A semi-empirical method of molecular orbital is applied to calculate the distribution of electric potential distribution in simple molecule models for the polymers after determining the configurations of orbital electron and proton. Furthermore the electron trap depth was calculated from difference between an electron affinity and conduction level for each polymers. As the model of polar polymers, Polycarbonate (PC), Polyethyleneterephthalate (PET), Polyethylenenaphthalate (PEN) and Polyimide (PI) are chosen. The relationships were also investigated on the simulated models of Polyethylene (PE), Polytetrafluoro-ethylene (PTFE), Polypropylene (PP) and Polystyrene (PS) as typical non-polar polymers. In the case of polar polymers, it is found that the electron traps were basically consisted of carbonyl group and benzene ring, and the trap depth equals to electron affinity which is always positive polarity. In the case of non-polar polymers, the conduction level equals to the electron affinity of PE and the trap depth equals to the difference between the conduction level and each electron affinity of polymer.