Superior organic
light-emitting transistors (OLETs) materials require two conventionally
exclusive properties: strong luminescence and high charge mobilities. We
propose a three-state model through localized diabatization to quantitative
analyze excited state structures for various herringbone (HB) H-aggregates and
demonstrate that for some investigated systems, the low-lying intermolecular
charge-transfer (CT) state couples with the bright Frenkel exciton (FE) and
forms a dipole-allowed S<sub>1</sub> that lies below the dark state, proceeding
strong luminescence. Specifically, such conversion in luminescence properties
occurs when the electron- and hole-transfer integrals (
and
) are of the same
sign and
is notably larger than the excitonic coupling
(<i>J</i>), i.e.,
. This theoretical
finding can not only explain and rationalize recent experimental results on DPA and dNaAnt, both
with OLET property, but also unravel an exciting scenario where strong
luminescence and high charge mobilities are compatible, which will considerably
broaden the aperture of novel OLET design.
Ionic to neutral conversion induced by resonant excitation of molecular vibrations coupled to intermolecular charge transfer
