ABSTRACT
Transition metals ions coordinated to organic ligands give rise to the most intense light emitters known in the field of OLEDs. These devices also have a few drawbacks: they present a relatively complex internal physical mechanism for electrical carrier recombination, have a large spectral emission bands, and some of them are based on expensive transition metals; however, and in spite of all the final result is a really surprising brightness. Naturally, these transition metals complexes are serious candidates for general lighting and even for decorative and architectural environment illumination, as, besides the high brightness, widely spectral colors are also obtained. This chapter addresses the fundamental notions about transition metal-based OLEDs, starting, as expected, with a discussion about the physical mechanisms of their radiative decay, setting ground for the understanding of the second part of the chapter, dedicated to OLEDs development and device structures employed. Some aspects of the chemical structure nature and the corresponding device working mechanisms are also focused, including a special discussion on light electrochemical cells (LECs) based on the observed redox behavior (although it must be noted that for the scope of this book those devices will be generically designated as OLEDs). The final
goal is to establish knowledge for further (and improvements) developments in this field.
