Emerging Generation III solar cell technologies employ active layers in thin-film formats, many on flexible inexpensive substrates, manufactured by area-scalable processes. Interfacial processes occurring at nanometer length scales in thin-film photovoltaic (PV) technologies are the thrust of CISSEM’s collaborative and synergistic research efforts, in particular at organic/metal oxide, organic/metal and metal oxide/metal oxide interfaces. The chemical and physical processes that occur at these interfaces can control the efficiency, lifetime, and manufacturability of thin-film PVs, and so must be understood and improved to support the desired growth of PV technologies and the U.S. renewable energy portfolio. Some of the most sophisticated Generation III thin-film PV technologies have ten’s of critical interfaces.
The need to understand interfacial charge transfer processes in Organic PVs (OPVs) and related thin-film photovoltaic systems is described in the U.S. DOE Report “Basic Research Needs for Solar Energy Utilization.” CISSEM scientists and engineers are undertaking an integrated, multi-investigator, multi-site effort through four Major Goals to understand how interface composition, morphology, and electronic properties can be controlled and improved to affect thin-film PV performance. These four Major Goals address the basic science of interfaces through theory, characterization, materials, and devices respectively. The CISSEM research program creates new scientific understandings of the electronic properties of interfaces relevant to many complementary energy conversion systems, including thin-film PVs, energy storage, solar photocatalysis, and solid state lighting