THE FORMATION AND RECOMBINATION OF ELECTRON-HOLE PAIRS IN THE MATRICES HALOGENATED DERIVATIVES POLY–N–EPOXYPROPYLCARBAZOLE DOPED WITH POLYMETHINE DYE

Abstract

Singlet and triplet states of the cationic polymethine dye in polymers – derivatives of poly-N-epoxypropylcarbazole with heavy atoms of different chemical nature are studied. It is shown that the presence of heavy atoms in the structure of the polymer leads to the appearance and buildup of the dye phosphorescence due to the growth of the spin-orbit interaction in the dye molecule and an increase in the rate of singlet-triplet transitions. An additional channel of relaxation of excited states of the dye in polymer films with a hole type of conductivity is the formation and recombination of electron-hole pairs, which is manifested in the appearance of recombination luminescence. Decrease in the intensity of recombination luminescence was recorded at measuring of the long-lived luminescence of a dye in an external magnetic field and without it. The time-dependent nature of the magnetic effect is the result of competition between the singlet and triplet channels of the formation of the electron-hole pairs.

Keywords: poly-N-epoxypropylcarbazole, polymethine dye, films, recombination luminescence, heavy atom effect.