exciton

Singlet fission, where an electronically excited singlet on one chromophore converts into a doubly excited state on two, has gone from a curiosity in organic photophysics to a potential pathway for increasing solar energy conversion efficiencies.

We show that the absorption spectrum in semiconducting nanotubes can be determined using the bosonization technique combined with mean-field theory and a harmonic approximation. In this framework, a multiple band semiconducting nanotube reduces to a