The invention relates to an organic blue phosphorescent main body material with
fluorene as a center
unit structure, and a preparation method and application thereof in a blue organic light-emitting
diode (
OLED). In the material,
fluorene is used as a main body structure, and different
electron properties of groups are bonded to 3-, 6- and 9- positions of
fluorene, thereby the
conjugated system of the main body material is effectively reduced, the effective molecular weight of the compound is increased, and the triplet energy and
glass transition temperature of the material are improved to some extent. In addition, the polarity of the compound can be adjusted by drawing / withdrawing
electron groups; compared with the commonly used blue phosphorescent main body materials including 4,4'-(9-
carbazole)-
biphenyl (CBP) and N,N'-dicarbazoyl-1,3-
benzene (m-CP), the efficiency roll-off problem under a high
luminescence condition of the blue phosphorescent
OLED devices is effectively solved under a condition of appropriate polarization rate; and the main body material can be widely used in the organic light-emitting field.