Rational design of multifunctional star-shaped molecules with a 1,3,5-triazine core and different arms for application in organic light-emitting diodes and organic solar cells.

A series of star-shaped 1,3,5-triazine derivatives for intended application in organic light-emitting diodes (OLEDs) and organic solar cells (OSCs) were investigated theoretically to explore their optical, electronic, and charge-transport properties. Analysis of their frontier molecular orbitals (FMOs) indicated that vertical electronic transitions associated with absorption and emission by these derivatives can be characterized as intramolecular charge-transfer (ICT) processes. The calculated results show that the optical, electronic, and charge-transport properties of the derivatives are influenced by the end groups and π-bridges present. Our results suggest that the molecules under investigation could serve as donor materials in OSCs and/or luminescent materials in OLEDs. In addition, all of the molecules are expected to be promising candidates for hole- and electron-transport materials. Based on our results, we were able to propose a rational method of designing multifunctional materials for application in OLEDs and OSCs. Graphical abstract A series of multifunctional star-shaped small molecules were investigated as charge-transport and luminescent materials for OLEDs as well as charge-transport and donor materials for OSCs.