No abstract

Material layers at electrode/semiconductor interfaces are fundamental for the photovoltaic properties of polymer solar cells. The relationship between open‐circuit voltage (VOC) and the work function (φ) of these interface layers is still a matter of debate. Simulations, together with experiments on over more than 20 cell architectures based on P3HT:PC60BM, enabled us to analyze the physical dependence of VOC on φ. In particular, when the work function of the contacts is well inside the gap we observe that performance depends strongly on even small variations of φ. On the other hand, when it approaches the energy levels of the semiconducting polymers, device operation becomes the most efficient and less sensitive to variations in φ. Furthermore, by varying the Gaussian density of states (DOS) of the active blend we were able to show that VOC performance depends significantly also on the DOS. Our study based on the simultaneous variation of transport layers represents a promising method to optimize the design and performance of polymer solar cells. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 690–699

A novel class of ordered mesoporous titania scaffolds prepared via colloidal lithography is attractive for perovskite-based solar cells thanks to the increased light-trapping inside the perovskite layer induced by the feedback structure and to the improved perovskite film.

No abstract

In this work, we present the realization and characterization of bulk‐heterojunction (BHJ) solar cells in which we use a spin‐coated polyethylenimine‐ethoxylated (PEIE) layer as electron‐transporting layer deposited from a fully water‐based solution. We investigated several concentrations of PEIE in aqueous solution and characterized the chemical and electrical behavior of PEIE‐coated fluorinated tin oxide (FTO) substrates. We realized BHJ solar cells using P3HT:PC60BM as active layer achieving a maximum efficiency of 4 % that outperform the device fabricated using a 2‐methoxyethanol‐based PEIE solution considered as reference. Moreover, devices fabricated with the water‐based PEIE solution showed a higher shelf‐life stability compared to those made with the 2‐methoxyethanol‐based PEIE solution. The performances of the devices realized with the water‐based solution were characterized over a period of more than 6 months showing a decrease of 30 % in efficiency.