Blue electroluminescence of a novel Zn2+–β-diketone complex with a carbazole moiety

In this letter, a novel zinc complex of Zn(ECTFBD)2 was synthesized by an environment-friendly grinding technique in high yield. Its structure was confirmed by 1H NMR, MS and EA. HECTFBD is 1-(9-ethyl-9H-carbazol-3-yl)-4,4,4-trifluorobutane-1,3-dione. Zn(ECTFBD)2-based light-emitting devices were fabricated. The architecture of the devices was ITO/PEDOT (40 nm)/100 wt% PVK: 40 wt% OXD-7: x wt% Zn(ECTFBD)2 (85 nm)/CsF (1.5 nm)/Al (100 nm), where x = 1, 5, and 10 (relative to the mass of PVK and OXD-7). The three devices displayed blue emissions with peaks at 450, 458, and 460 nm, respectively. A maximum luminous efficiency of 0.86 cd/A and a luminance of 228 cd/m2 were achieved by the 1 wt% doped device. So, we demonstrated further that Zn2+–β-diketone complexes can be effectively severed as a class of new electroluminescent materials. In addition, the thermal stability of Zn(ECTFBD)2 was tested and the UV–vis and photoluminescent behaviors of Zn(ECTFBD)2 in CH2Cl2 were investigated.

Graphical abstractA novel Zn2+–β-diketone complex with a carbazole moiety was synthesized by an environmentally friendly grinding technique. The OLEDs of the zinc complex-doped into the blend of PVK and OXD-7 were fabricated; a blue emission with a peak at 450 nm from the zinc complex was achieved.Figure optionsDownload full-size imageDownload as PowerPoint slide