The synthesis and photoelectrical performances of perylenediimide-based devices as an interface layer in metal-organic-semiconductors

The symmetric and asymmetric perylenediimide (PDI)-based organic ligands Ph-PDI-Ph (1), Pyr-PDI-Pyr (2), and Pyr-PDI-Ph (3) were synthesized. Au/(Pyr-PDI-Ph)/p-Si (D1), and Au/(Ph-PDI-Ph)/p-Si (D2) devices were fabricated using thermal evaporation and their photodiode performances were examined under the irradiation of 100 mW.cm(-2) at -2 V. In addition to the analysis of photodiode performances, the electrical properties depending on temperature and frequency of these structures were calculated using three different methods, which are the thermionic emission, Norde function, and Cheung&Cheung function. Furthermore, the molecular geometry, electronic absorption spectra, HOMO-LUMO and MEP surface analysis of the molecules mentioned were computed using the DFT/B3LYP method with 6-31 G (d,p) basis set and DFT calculations supported both the non-planar structures or propeller structures and compatibility of the theoretical results with the experimental data. The results supported that the fabricated D1 and D2 devices can form a basis for practical applications in optoelectronic device applications, especially photodiodes and photodetectors.