Coloquio de Física - High-efficiency solar cells: from silicon heterojunctions to perovskite/silicon tandems

   Departamentos        Ciencias - Sección Física

Ponente: Lars Korte (Helmholtz-Zentrum Berlin, Institute for Silicon Photovoltaics, Alemania) Photovoltaics (PV) is already one of the most important sources of renewable energy, and has seen dramatic cost reductions over the last years. With a market share of about 90%, silicon solar cells are the dominant PV technology. In this context, I will present Helmholtz-Zentrum Berlin's contributions to two silicon-based high-efficiency solar cell technologies: amorphous/crystalline silicon heterojunction (SHJ) solar cells, and perovskite/SHJ tandem cells. While silicon heterojunction cells are a mature technology and already in production, perovskite/SHJ tandem solar cells are a very recent concept (first results are from 2015) to overcome the theoretical efficiency limit of single junction cells. Here, a second solar cell based on organic-inorganic perovskite materials and their contacts is processed directly on the silicon bottom cell. These tandem cells thus offer an inexpensive option to significantly boost state-of-the-art silicon single junction cells. I will discuss the challenges of developing and optimizing materials and devices. Furthermore, I will show in a few selected examples how advanced analytics and numerical simulations can be used to relate basic materials properties to parameters of the final PV device.