Aggregation-enhanced luminescence and vibronic coupling of silole molecules from first principles

• Aggregate formation in molecular solids usually quenches the luminescence, a piece of bad news for molecular electronic devices. However, siloles present extremely high luminescent efficiency in solid state as well as in aggregation, but have almost no luminescence in solution. By employing a first-principles calculation to study excited states and vibronic couplings, we find that it is the low-frequency twisting motions of side rings which enhance the nonradiative decay. These motions can be suppressed either by solid-state packing, by aggregation formation in polar solvents, or by increasing the solvent viscosity; thereby, the radiative decay becomes dominant, resulting in peculiar aggregate-induced emission phenomena in siloles.

Subject headings

NATURVETENSKAP  -- Kemi -- Teoretisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Theoretical Chemistry (hsv//eng)

Keyword

RESTRICTED INTRAMOLECULAR ROTATION; LIGHT-EMITTING-DIODES; THERMAL-STABILITY; INDUCED EMISSION; 2

3

4

5-TETRAPHENYLSILOLES; PHOTOLUMINESCENCE; POLYMERS; STATES

Theoretical chemistry

Teoretisk kemi

Publication and Content Type

ref (subject category)

art (subject category)