Carrier Dynamics in Pentacene|C60 Bilayer Solar Cell Investigated through the Magnetoconductance

Abstract

We demonstrate the magnetoconductance (MC) effect originated from depressing the spin mixing in encounter pairs under the external magnetic field provides quantitative information about the singlet fission, the charge recombination, and the trap-related dynamics with triplet exciton in a bilayer device of pentacene (Pen) and fullerene (C60). Three MC effects in low-, moderate-, and high-fields were detected in the bilayer device at room temperature. Kinetic analysis of the low-field MC effect showed that the charge recombination yield at the Pen|C60 interface is ∼1%. Quantum mechanical simulations for dynamics of spin-carrying pairs following the conservation rule of spin angular momentum in recombination showed that the moderate- and high-field MC effects are caused by, respectively, the trap-related dynamics with triplet exciton and the singlet fission with a maximum yield of 52% in the layers. The quantitative information obtained by investigating the MC effect will contribute to the development of hig...