Аннотация:A new technique for analysis of p 8-Hq-T diagram was developed for the metal-organic phosphors with symmetrical ligands and corresponding diagram was studied for tris-(8-hydroxyquinoline)aluminium (III) – Alq 3 . We showed that for α-Alq 3 prepared as single-phase crystalline samples with controlled defect structure allowed varying the cell volume, chemical activity and electrical properties of the crystalline preparation and OLED made on its basis.