Four kinds of 8-hydroxyquinoline rare earth chelate are synthseased and employed as the emitters in organic thin film electroluminescence (OTFEL) cells

respectively.Their characteristics of current density-voltage (

I-V

) and EL spectra are studied.It is found that the emitting spectra are wide band (the half width is about 100nm)

instead of the special emitting spectra from the rare earth ions.In addition

by analysingthe tendency of EL emitting intensity with the other metal chelates of 8-hydroxyquinoline and its derivative in previous reports.It is suggested that the EL brightness of 8-hydroquinoline chelates containing light metals is higher than that of 8-hydroquinoling chelates containing heavy metals.