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Black ALD Magic

Increasing solar cell efficiency with atomic layer deposition

A very interesting doctoral dissertation in the field of semiconductor technology will be defended tomorrow in the Department of Micro- and Nanosciences of Aalto university School of Electrical Engineering.

Päivikki Repo is defending her PhD thesis about black silicon passivated by atomic layer deposition. Part of this work contributed to the world record on black silicon solar cell efficiency, published in Nature Nanotechnology last year.

In her research, Päivikki has improved the efficiency of solar cells by passivating the surface with different ALD thin film coatings with good results.

Surface passivation becomes even more important in the case of black silicon (b-Si). In the thesis, Päivikki presents that ALD Al2O3 can solve the issue of increased surface re-combination by providing completely conformal coatings and excellent passivation also on nanostructured surfaces. This proves the potential of using the combination of black silicon and ALD Al2O3 in different photovoltaic devices.

As is often the case with demanding ALD research applications, the ALD layers in Päivikki’s research were accomplished using Beneq ALD equipment.

We congratulate Päivikki and wish her all the best in her defense on Friday!

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