Basic solar cell characteristics were examined in an organic bulk heterojunction device. The active layer is a spincoated organic blend of a pmaterial (MEH-PPV) and an n-material (the fullerene derivative PCBM), sandwiched between a transparent ITO-PEDOT/PSS electrode and an Al/LiF back-contact. We carried out light and dark I-V and spectral response measurements and measured the transparency o...

We report different solar cell designs which allow a simple electrical connection of subsequent devices deposited on the same substrate. By arranging the so-called standard and inverted solar cell architectures next to each other, a serial connection of the two devices can easily be realized by a single compound electrode. In this work, we tested different interfacial layer materials, such as p...

Two newly synthesized naphthodithiophene-based copolymers, PNB, exhibit a low optical bandgap of ∼1.64 eV with which the solar cells fabricated from the blend of PNB and PC(71)BM afforded a power conversion efficiency of 5.3% with external quantum efficiency over 60% in a broad spectral range.

Amorphous carbon (a-C) has the potential to provide properties important to solar photovoltaics that are comparable to those of silicon-based materials with further advantages such as low cost, solution processing, air stability, and higher thermal resistance. We employ accurate computational approaches to explore and understand active layers based on bulk heterojunctions containing a-C. Our re...

Morphology of organic photovoltaic bulk heterojunctions (BHJs) - a nanoscale texture of the donor and acceptor phases - is one of the key factors influencing efficiency of organic solar cells. Detailed knowledge of the morphology is hampered by the fact that it is notoriously difficult to investigate by microscopic methods. Here we all-optically track the exciton harvesting dynamics in the full...