Luminescent transition-metal complexes and their applications in electroluminescence

By taking the advantages of phosphorescence, thermally activated delayed fluorescence, and metal-assisted delayed fluorescence, luminescent transition-metal complexes (LTMCs) are a promising class of photofunctional materials for the electroluminescence, which can make full use of their triplet and singlet states and then remarkably boost the efficiency of devices. In this chapter, the recent research progress on the LTMCs (including iridium(III), platinum(II), gold(I/III), copper(I), ruthenium(II), rhenium(I), osmium(II), rhodium(III), palladium(II), silver(I), tungsten(VI), manganese(I/II), iron(II/III), nickel(0/II), zirconium(IV), and chromium(III) complexes, etc.) as the emitters for electroluminescence will be summarized and discussed. The design strategies on the molecular structures, and photophysics of these LTMCs and their electroluminescence applications are presented in detail. In addition to the most popular iridium(III) and platinum(II) complexes involved in the design of organic electroluminescence (organic light-emitting diodes, light-emitting electrochemical cells, etc.), the relatively less explored LTMCs and their emerging applications in organic electroluminescence are also included.