Posted: June 30, 2010

Dye (Graetzel) solar cell research in Aalto University

(Nanowerk News) The 2010 Millennium Technology Prize was awarded in June 2010 in Helsinki to Professor Michael Grätzel, who discovered dye-sensitized solar cells (DSC), also known as "Grätzel cells". The basic principle of the DSC resembles the photosynthesis of plants; and these cells have a major potential for mass production. The development of DSCs calls for a multidisciplinary research approach combining several fields of physics, chemistry, and material science. In the New Energy Technologies Group, led by Professor Peter Lund from the Department of Applied Physics at Aalto University, research in DSCs has been carried out since 2001.
The DSC group consists of three post-doctoral researchers, three doctoral students, and several research assistants. One main focus of the research is on cell preparation on flexible foils, metals, and plastics to enable roll-to-roll mass production. The research on flexible DSCs deposited on metals has led to record-breaking efficiencies in energy conversion.
In addition, the group is recognized internationally for its contributions to modeling and the characterization of DSCs, as well as for studies on the degradation mechanisms and the long-term stability of the cells. The group is currently working to scale up their flexible DSC technology to 100 cm2 prototype modules using screen printing.
Technically, DSC is an electrochemical solar cell, where light absorption and current generation occur in dye molecules. The cell has a sandwich-like structure: there are two electrodes which are traditionally deposited on glass, and the space between them is filled with liquid or solid electrolyte.
DSCs have several advantages over conventional silicon photovoltaic technologies: high energy conversion efficiencies can be reached using cheap and abundant materials. Furthermore, DSCs can be prepared using simple printing technologies without requiring a cleanroom.
The manufacturing is even compatible with high-throughput roll-to-roll production on large areas when flexible substrates are used. These solar cells have great potential for economic large-scale solar electricity generation, but they are also interesting in the near term as an enabling energy technology for mobile and printed electronics applications.
Research topics
  • Plastic and metal substrates, advanced materials
  • Characterization, optimization, and cell modeling
  • Degradation mechanisms and long-term stability
  • Scaling-up to prototype modules
  • Source: Aalto University