Quantum cutting using organic molecules.

A methodology is presented in which a combination of quantum electrodynamics, time-dependent perturbation theory, and computational electronic structure analysis allow the prospect for organic quantum cutting to be quantitatively examined from first principles. The internal quantum yield of quantum cutting is ultimately expressed in terms of rate equations that account for all relevant processes. These are populated with excited state properties found using time-dependent density functional theory and configuration interaction methods. The rate equations are incorporated into an optimization routine in which the quantum yield is maximized by changing the spacing and orientation of the molecules. Adapting design criteria first developed for energy pooling, a system of squarylium dye III and fluorene was identified as being capable of carrying out meaningful quantum cutting. With relative position and orientation optimized, the internal quantum yield of this test system is predicted to be 1.2. In the absence of non-radiative decay, the internal yield is predicted to be 1.9.