Dye sensitized solar cells (DSSCs) – also known as Grätzel solar cells (Prof.dr. Grätzel EPFL-honorary doctorate Hasselt University) - are considered as a promising low-cost alternative to conventional inorganic semiconductor photovoltaic devices. DSSCs, using nanoporous TiO2 electrodes, ruthenium-based complexes dyes and liquid electrolytes, reach power conversions up to 10% under AM 1.5 (100 mW/cm2) solar illumination. The presence of the liquid electrolytes requires special attention regarding sealing, stability and multi-cell module manufacturing.
As an alternative to the liquid electrolyte, solid state hole conductors are being investigated towards the development of the solid state dye-sensitised solar cell, also termed as hybrid solar cells due to the combination of organic and inorganic semiconductors.
Recent interdisciplinary activities at IMO-IMOMEC include the controlled growth of nanocolumnar ZnO - from the IPC-group - which is studied in combination with organic semiconductors to obtain hybrid solar cells with a record efficiency of 2.8 % and the demonstration of ‘Green’ Grätzel solar cells using environmentally friendly processing.