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Organic solar cells are an interesting and promising photovoltaic technology which has faced a strong development in the last decade. Still, there is plenty of room for device improvement. Many different parameters, not always easy to control, determine the final power conversion efficiency. In this work we analyze the impact of unbalance charge carrier mobilities. It is known that a different charge mobility for electrons and holes determines a reduction in performance. We have developed a numerical model that includes the 3D morphology of the blend in the simulator. With this model we are able to observe the charge and current density distribution across the blend at different working points. We have investigated the effect of charge unbalance to solar cell performance.

Herein, we report a facile method of direct photodissociation of toluene molecules to photoluminescent carbon dots (CDs) under pulsed laser irradiation in the absence of surfactants or catalysts. The as-synthesized CDs with diameters 1.3–4.0 nm present regular emission peaks and the crystallographic structure of these species has been identified as graphite 2H from the analysis of high resolution transmission electron microscope (HRTEM) images, X-ray photoelectron spectroscopy (XPS) and Raman spectrum. In addition, First-Principle calculations were performed to discuss the photon-induced excitation in the photodissociation process. The results demonstrate that electrons can be transited from Highest Occupied Molecular Orbital (HOMO) to Lowest Unoccupied Molecular Orbital (LUMO) in toluene molecule by 248 nm single photon excitation process and the Stark effect plays a crucial role in the photodissociation process. These CDs exhibit excellent stable emission due to the stability of crystal structure, which could be considered for promising luminescent applications.