Effect of high density excitons on fluorescence of naphthalene-tetracyanobenzene complex crystal

An exciton-exciton collisional annihilation was studied with the naphthalene-tetracyanobenzene complex crystal by observing and analyzing the fluorescence decay curve; the second-order decay constant was determined to be 3 × 10−13 cm3 sec−1 at 77°K. A new type of inhomogeneous broadening effect was found for the fluorescence from the complex crystal excited in high density and was interpreted to be due to the strong electrostatic interaction between the charge-transfer excitons with large dipole moments.