One- and two-photon absorption spectra of dibenzoterrylene

Dibenzoterrylene (DBT) has garnered interest as a potential single-photon source. To have a better grasp of any possible limitations of using DBT for this application, a better understanding of its optical properties is needed. We use a configuration interaction method to calculate the many-body wave functions of DBT and we use these wave functions to calculate its optical properties. We calculate the linear absorption spectrum and the spatial distributions of electrons involved in several bright transitions. We also calculate the two-photon absorption spectrum of DBT and show that there are several excited states that are bright due to two-photon absorption. Except at high photon energies, we predict that there are no competing optical processes regarding the use of DBT as a single-photon source. Our calculations provide details of the optical properties of DBT that are interesting in general and useful for considering optical applications of DBT.