Figure 5
Schematics of bias-dependent formation pathways.
(a) Schematic representation of the electric field F(V) dependence of the energy levels of SE (ESE), TE (ETE), singlet (triplet) polaron pair (PP) (ESPP(TPP)) and ground state (EG). ΔES(T) is the energy separation between SE (TE) and PPs. The energy levels of PPs decrease in proportion to the electric field and thereby the generation rate of SE (TE), GS(GT), depends on the field. (b) Bias-dependent formation pathways of excitons derived from the present study. The red solid (broken) arrows indicate the pathways strongly (weakly) depending on the bias. Remarkable bias effects only appear on emission from SE due to the inefficient intersystem crossing (ISC) yield in MEH-PPV.
