Black silicon can take efficiency of solar cells to new levels

Jan 18, 2013

Scientists at Aalto University have demonstrated results that show a huge improvement in the light absorption and the surface passivation of silicon nanostructures. This has been achieved by applying atomic layer coating. The results advance the development of devices that require high sensitivity light response such as high efficiency solar cells.

"This method provides extremely good surface passivation. Simultaneously, it reduces the reflectance further at all wavelengths.These results are very promising considering the use of black silicon (b-Si) surfaces on solar cells to increase the efficiency to completely new levels," tells research scientist Päivikki Repo.

More effective surface passivation methods than those used in the past have been needed to make black silicon a viable material for commercial applications. Good surface passivation is crucial in photonic applications such as solar cells. So far, the poor charge carrier transport properties attributed to nanostructured surfaces have been more detrimental for the final device operation than the gain obtained from the reduced reflectance.

Black silicon (b-Si) can also be used in other technologies than solar cells. Numerous applications suggested for b-Si include drug analysis.

Black silicon has been a subject of great interest in various fields including for its ability to reduce the surface reflectance even below 1 per cent. However, many b-Si applications - especially solar cells - suffer from increased surface recombination resulting in poor spectral response. This is particularly problematic at short wavelengths.

The research has just been published in the Journal of Photovoltaics.

Explore further: U.K. grocery store to power itself on biogas generated from its own food waste

More information: Repo, A. et al., Effective Passivation of Black Silicon Surfaces by Atomic Layer Deposition, IEEE Journal of Photovoltaics, JPV January 2013, pp. 90-94. dx.doi.org/10.1109/JPHOTOV.2012.2210031

add to favorites email to friend print save as pdf

Related Stories

Nanostructures improve solar cell efficiency

May 26, 2011

To make solar cells a competitive alternative to other renewable energy sources, researchers are investigating different alternatives. A step in the right direction is through new processes that change the ...

Recommended for you

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Steven_Anderson
1 / 5 (1) Jan 18, 2013
can someone tell me the specifics and technical details of the improvement in practical applications...PLEASE.