Published on July 15th, 2013 | by James Ayre2
New Record Efficiency For Dye-Sensitized Solar Cells
A new efficiency record for dye-sensitized solar cells has been achieved by researchers at EPFL in Switzerland — the new record of 15% has now been achieved thanks to a new fabrication process created by the researchers.
Dye-sensitized solar cells (DSSCs) are a very promising type of solar cell — largely as a result of their relatively low cost, transparency, and relatively high power conversion efficiencies under cloudy and artificial light conditions. Until this new breakthrough, though, they had fallen short of conventional silicon-based solar cells with regard to overall efficiency — but this was primarily just as a result of “the inherent voltage loss during the regeneration of the sensitizing dye,” something which could certainly be addressed, as it now has been.
The press release from EPFL provides details:
EPFL scientists have developed a state solid version of the DSSC that is fabricated by a new two-step process raising their efficiency up to a record 15% without sacrificing stability.
The new solid-state embodiment of the DSSC uses a perovskite material as a light harvester and an organic hole transport material to replace the cell’s electrolyte. Typical fabrication of this new DSSC involves depositing a perovskite material directly onto a metal-oxide film. The problem is that adding the entire material together often causes wide variation in the morphology and the efficiency of the resulting solar cell, which makes it difficult to use them in everyday applications.
Michael Grätzel’s team at EPFL has now solved the problem with a two-step approach: First, one part of the perovskite is deposited in to the pores of the metal-oxide scaffold. Second, the deposited part is exposed to a solution that contains the other component of the perovskite. When the two parts come into contact, they react instantaneously and convert into the complete light-sensitive pigment, permitting much better control over the morphology of the solar cell.
Thanks to the new process, the record power-conversion efficiency for DSSCs has climbed to an impressive 15% — which exceeds the power conversion efficiencies of conventional, amorphous silicon-based solar cells. The researchers think that their work will likely “open a new era of DSSC development, featuring stability and efficiencies that equal or even surpass today’s best thin-film photovoltaic devices.”