ИСТИНА

Organic electronics have made significant progress in the last decade.1 The most successful results have been achieved in OLED technology. The crystalline organic materials with 4N purity allowed solving the problem of high efficiency and long stability. Further improvement of the functional properties of material could be based on fundamental investigations of organic semiconductors in terms of solid state chemistry. In the case of crystalline chemical compounds according to the thermodynamic laws at T > 0 K the generation of atomic point defects is an inevitable process. For non-doped chemical compounds atomic point defects result from deviation of the composition from stoichiometric ratio, so called non-stoichiometric defects. Unfortunately to the date there are no commonly used methods of nonstoichiometry determination of inorganic compounds1. In the case of organic compounds the problem of nonstoichiometry has become actual because of the further development of organic semiconductors. We have developed the efficient technique for the analysis of pi-T-x diagram of metal organic coordination compounds2 which are used as light emitting materials in multilayer OLED devices. Using this technique pligand-T diagrams were plotted for a number of coordination compounds based on 8-oxyquinolinol and its derivatives as ligands with different metals such as Al, Ga, In, Pt. The diagrams were used for determination of synthesis conditions of compounds with varied defect structure. It was demonstrated that the lattice parameters, chemical activity, and electrical properties of the crystalline organic compounds depended upon the synthesis conditions within the homogeneity range. [1] I. Avetissov, E. Mozhevitina, A. Khomyakov, T. Khanh, Cryst. Res. Technol. 2015 50 (1), 93–100. [2] I.Ch. Avetissov, A.A. Akkuzina, N.N. Kozlova, R.I. Avetisov, CrystEngComm 20, 930-936