Charge Transport Properties of a Series of Metal Quinolates Utilising Dispersion-Corrected Density Functional Theory

Abstract

The electronic and charge transport properties of Metal-Quinolates (Metal = Li, Na, K, Rb and Cs) compounds are theoretically investigated using AustinFrisch-Petersson functional with dispersion (APFD) corrected density functional theory (DFT). The calculated energy gap between highest occupied molecular orbital and lowest unoccupied molecular orbital ranges from 3.40 eV for LiQ to 0.93 eV for CsQ. The ionisation potential, electron affinity and chemical hardness of the compounds are calculated. We found that the electron hopping rate, kelectron of CsQ is around 150 times greater than LiQ. We suggest that CsQ is the most efficient charge injecting or transport material for organic light-emitting diodes (OLEDs). Dimer formation is desirable with all M-Quinolate with different electronic structures and (CsQ)2 dimer shows the lowest dimerisation energy.