Simplice Koudjina
University of Abomey-Calavi, Benin
Title: charge transfer electronic states and reorganization energy of oled npd in amorphous and crystalline structure for organic electronics devices
Biography
Biography: Simplice Koudjina
Abstract
Renewable energy alternative promising with Organic photovoltaic cells convert sunlight into electricity. They are several polymeric materials that are light, flexible, inexpensive to manufacture and adjustable at molecular level. To this end, an investigation of charge transport by ADF/PBE0/DZ and TD-DFT quantum methods in the molecule-to-molecule hopping regime through charge transfer integrals and reorganisation energies was performed on an OLED α-NPD semiconductor in amorphous and crystalline structure, exposing its optoelectronic properties in aggregate configurations. For each α-NPD configuration with 1050 isolated monomers molecules, the transfer integrals of more than 10.000 dimers were determined and rationalised by overlapping HOMO or LUMO orbitals, for both hole and electron transport. The comparison of the average charge transfer integrals in the two structures suggests that holes move as fast in amorphous structure then in crystalline structure, which allows to propose in the performance the aggregate in amorphous structure for Organic Electronic Devices.