Ab initio calculation of ionization potential and electron affinity in solid-state organic semiconductors

作者:Kang Youngho; Jeon Sang Ho; Cho Youngmi; Han Seungwu*
来源:Physical Review B, 2016, 93(3): 035131.
DOI:10.1103/PhysRevB.93.035131

摘要

We investigate the vertical ionization potential (IP) and electron affinity (EA) of organic semiconductors in the solid state that govern the optoelectrical property of organic devices using a fully ab initio way. The present method combines the density functional theory and many-body perturbation theory based on GW approximations. To demonstrate the accuracy of this approach, we carry out calculations on several prototypical organic molecules. Since IP and EA depend on the molecular orientation at the surface, the molecular geometry of the surface is explicitly considered through the slab model. The computed IP and EA are in reasonable and consistent agreements with spectroscopic data on organic surfaces with various molecular arrangements. However, the transport gaps are slightly underestimated in calculations, which can be explained by different screening effects between surface and bulk regions.

  • 出版日期2016-1-22