The present invention discloses an iridium complexes and the organic EL device employing the iridium complexes as light emitting guest of emitting layer can display good performance like as lower driving voltage and power consumption, increasing efficiency and half-life time. Additional, the present invention provide the suitable emitting host (H1 to H6) to collocate with the energy level of iridium complexes for the present invention. Also provided a novel preparation method to synthesize the novel ligand such as 6-bromo-3,3-dimethyl-1-phenyl-1,3-dihydroindeno[2,1-b]carbazole.