Pinholes are Pitfalls for High Performance Solar Cells
http://www.oist.jp/news-center/news/2015/1/28/pinholes-are-pitfalls-high-performance-solar-cells[font face=Serif][font size=5]Pinholes are Pitfalls for High Performance Solar Cells[/font]
30 Jan 2015
[font size=3]The most popular next-generation solar cells under development may have a problem the top layer is full of tiny pinholes, researchers at the Okinawa Institute of Science and Technology Graduate University in Japan have found.
The majority of high-performance solar cells under development use a combination of materials including perovskite and
spiro-MeOTAD. These cells are far cheaper than traditional silicon-based solar cells, and their efficiency has been increasing significantly in the past few years. But perovskite, which is the layer that converts sunlight to electricity, degrades quickly.
OIST researchers believe they have identified a key culprit for this problem.
Miniscule pinholes in the spiro-MeOTAD layer -- most so small they cannot be seen even with a light microscope -- may be creating easy pathways for water and other gas molecules in air to diffuse through the thin film and degrade the perovskite.
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http://dx.doi.org/10.1021/cm504022q