Optical and Electrical Properties of New Perylene Diimide Thin Films

Abstract

Perylene diimides with high photosensitivity and high electron mobility have attracted much attention for use in organic semiconductor devices. In this investigation, thin films of six new perylene tetracarboxylic diimides (PTCDI) were fabricated by spin coating, on glass as substrate, and their optical and electrical properties were studied. The absorption spectra of thin films of PTCDI furnished more informative bands than those of the compounds in solution. The morphology of the thin films was examined by scanning electron microscopy and x-ray diffraction. The absorption spectra and I-V characteristics of the compounds were affected by their molecular structures. HOMO-LUMO band gaps of the films were in the range 1.9-2.0 eV. Band gaps calculated by use of computational methods were comparable with experimental results.

The effect of ionic liquids on the nucleation and growth of perylene films obtained by vapor deposition

“…The same behaviour has been described for perylene diimide films as well as for other PAHs such as tetracene and pentacene. 50,[81][82][83] Optical band gaps of 2.77 and 2.45 eV can be estimated from the optical spectrum of perylene in solution and the thin-film state, respectively. This estimation was made from the offset wavelength derived at the lower energy absorption band.…”