Abstract A series of zinc complexes has been synthesized and utilized as fluorescent materials in organic light-emitting diodes (OLEDs). All prepared complexes were characterized by elemental analysis (CHN), UV–vis, FT-IR and 1H NMR spectroscopy. The energy levels of zinc complexes were determined by cyclic voltammetry measurements. Devices with fundamental structure of ITO/PVK:PBD (50nm)/zinc complexes/BCP (5nm)/Alq3 (25nm)/Al (180nm) were fabricated. A green electroluminescence was obtained from thin film complexes at 25nm thickness. When thickness of the complex bis(2-methylquinolin-8-olato)-bis[(acetato)-(methanol)zinc(II)] (B) in thin film decreased from 25nm to 20, 18, and 12nm, a white electroluminescence obtained. The white emission which was composed of blue and green attributed to the PVK:PBD blend and thickness of complex, respectively. With 12nm thickness of complex, a maximum luminance of 4530cd/m2 at a current density 398.32mA/cm2 with CIE coordinates of 0.22 and 0.36 at 20V was achieved.