White Organic Light-Emitting Diodes with Zn-Complexes

Abstract

This paper reviews OLEDs fabricated using Zn-complexes. Zn(HPB)2, Zn(HPB)q, and Zn(phen)q were synthesized as new electroluminescence materials. The electron affinity (EA) and ionization potential (IP) of Zn complexes were also determined and devices were characterized. Zn complexes such as Zn(HPB)2, Zn(HPB)q, and Zn(phen)q were found to exhibit blue and yellow emissions with wavelengths of 455, 532, and 535 nm, respectively. On the other hand, Zn(HPB)2 and Zn(HPB)q were applied as hole-blocking materials. As a result, the OLED efficiency by using Zn(HPB)2 as a hole-blocking material was improved. In particular, the OLED property of Zn(HPB)2 was found to be better than that of Zn(HPB)q. Moreover, Zn(phen)q was used as an electron-transporting material and compared with Alq3. The performance of the device with Zn(phen)q as an electron-transporting material was improved compared with Alq3-based devices. The Zn complexes can possibly be used as hole-blocking and electron-transporting materials in OLED devices. A white emission was ultimately realized from the OLED devices using Zn-complexes as inter-layer components.

Self-Assemblies of Zinc Complexes for Aggregation-Induced Emission Luminogen Precursors

“…The self-assembly of various zinc complexes shows novel emission properties. − Many zinc complexes have prospects as applied optoelectronic materials. − Besides enhanced chemical reactivity for catalytic reactions, − optoelectronic properties of zinc oxide necessitate the study of polynuclear zinc clusters possessing a ZnO 4 environment. − Solvent plays an important role in the synthesis of such zinc clusters or coordination polymers. , Design of ligands − and improvisation of noncovalent interactions of ligands are common ways to synthesize complexes with less conventional coordination numbers such as five-coordinated , zinc complexes. A careful look at the number of zinc complexes suggests that, irrespective of ligands, they show emissions near 400–430 nm with some exceptions. − Some d 10 zinc complexes show sample- and size-dependent fluorescence emissions, whereas in certain cases, aggregation-induced emissions (AIE) of zinc complexes are comparable to similar emissions by corresponding d 10 cadmium complexes .…”

“…A careful look at the number of zinc complexes suggests that, irrespective of ligands, they show emissions near 400−430 nm with some exceptions. 1−8 Some d 10 zinc complexes show sample-and size-dependent fluorescence emissions, 36 whereas in certain cases, aggregation-induced emissions (AIE) of zinc complexes are comparable to similar emissions by corresponding d 10 cadmium complexes. 37 Those observations together with the emergence of AIEgens of zinc complexes 38−41 and the development of newer aspects of AIEgens 42,43 make one curious to explore the emission behavior of simple zinc complexes.…”

Optoelectronic characterization of zinc complexes for display device applications

“…White organic light emitting devices and displays are the next generation energy saving light sources which could help to lower the energy crisis. Full color emissive materials have also attracted much attention as key components for OLED display devices with the high performance of red-greenblue light emitters with long life span materials [6][7][8][9].…”