Analysis of Charge Transport and Device Performance in Organic Photovoltaic Devices with Active Layers of Self-Assembled Nanospheres

Abstract

Nanoparticle (NP) assemblies are particularly appealing as active layers of organic photovoltaic (OPV) devices because their aqueous synthesis reduces the usage of chlorinated solvents and because the nanoparticle size, ratio, and internal structure can be controlled precisely. Understanding quantitatively the effects of active layer nanostructure on charge carrier transport in NP-assembly-based OPV devices is crucial in order to optimize device performance. Toward this end, in this study, we report results of numerical simulations of electron and hole transport in OPV devices with active layers consisting of P3HT:PCBM nanoparticle assemblies based on deterministic charge carrier transport models. The models account for the dynamics of bounded electron–hole pairs and free charge carriers, as well as trapped charge carrier kinetics, self-consistently with the electric field distribution in the device active layer. The models reproduce both transient photocurrents from time-of-flight (TOF) experiments and s...