Organic emitters

FIGURE 7.8 Molecular structures of several organic emitter materials. Their positions on the diagram are arranged as a function of their emission color with blue emitters on the left, green in the center, and red on the right hand side. 

In summary, for organometallic compounds the transition probability between the T, and the S0 states can be tuned by several orders of magnitude as compared to organic emitters. This is mainly induced by an increase of spin-orbit coupling. Thus, the radiative processes can well compete with the non-radiative ones. Consequently, organo-transition-metal compounds can exhibit efficient emissions (phosphorescence) and therefore are well suited as emitter materials for OLEDs. 

Zhang, Q., Tsang, D., Kuwabara, H., Hatae, Y., Li, B., Takahashi, T., Lee, S.Y., Yasuda, T., Adachi, C., 2015a. Nearly 100% internal quantum efQciency in undoped electroluminescent devices employing pure organic emitters. Adv. Mater. 27,2096-2100. 

Organic electroluminescent (EL) devices are the subject of study by many researchers because of their potential application as light-emitting devices which operate at low drive voltages. These devices are injection-type, in which carriers, such as electrons (radical anions) and holes (radical cations), are injected into the organic emitter layer where they recombine. It is, therefore, necessary for the component organic materials to possess carrier-transporting properties as well as fluorescence properties. 

Drni D (2005) Electrochemiluminescence from Organic Emitters. Chem Mater 17 1933... 

Figure 12.4 A selected range of organic emitter materials as a function of the peak...

Dini, D. (2005) Electrochemiluminescence from organic emitters. Chem. Mater., 17,1933-1945. 

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