ИСТИНА

(Bis(10-hydroxybenzo[h]quinolinato)beryllium (Bebq2) is an electron-transporting and fluorescent material used in organic light-emitting diodes. It exhibits excellent emitting and charge-transport characteristics. In this work we present the results of quantum-chemical calculations of Bebq2 molecule and its dimers in order to better understand the mechanism of charge transport in this material and its luminescence properties. We use multireference XMCQDPT2/CASSCF method to calculate the reorganization energies and hopping integrals for electron and hole transport in various dimers of Bebq2 that can occur in the solid phase. The same method is used to calculate the ionization potential, electron affinity and absorption and emission spectra of Bebq2 monomer. The results agreee well with the experiment. The key feature in small-molecular organic semiconductors is charge localization. Our technique can directly show, whether the charge carrier is localized or delocalized. In this respect, our technique is superiour to the energy splitting in dimer (ESID) method commonly used for calculating hopping integrals in organic semiconductors.