Electron and hole transport in the APFO3:PC61BM organic photovoltaic blends

In this paper, the electron and hole transport properties, and the possible presence of spatially correlated disorder in the APFO3:PC61BM organic blends are investigated. The temperature dependent current density-voltage (J - V) characteristics of the hole-only and electron-only devices based on the APFO3:PC61BM blends can be consistently described by using the improved extended Gaussian disorder model (IEGDM) and the extended correlated disorder model (ECDM), within which includes the carrier density dependence of the mobility in the Gaussian density of states and assuming either random or spatially correlated site energies. In contrast to the ECDM, the IEGDM provides a better description for both hole and electron transport. Based on the comparison of the intersite distance and fit quality of J - V curves between the IEGDM and ECDM, we argue that the analysis provides evidence for the absence of correlated disorder in the APFO3:PC61BM blends. Furthermore, it is found that energetic disorder is larger for holes than for electrons, and electron transport is intrinsically superior to hole transport.