Solar scientists rough up silicon panels to boost light capture

July 26, 2017, Osaka University
Solar scientists rough up silicon panels to boost light capture
Figure 1. Fabrication of ultralow reflectance polycrystalline silicon wafers by use of the developed technology. Credit: Osaka University

Power generation cost using solar panels depends on getting as much electricity out of the panels as possible while keeping the manufacturing costs low. Anyone who has considered installing solar panels might be aware of the trade-off between efficiency and the initial cost of the panels. Engineers and researchers are finding new ways to obtain power out of solar modules, but doing so without adding to their costs is becoming more and more difficult.

Now a team of scientists at Osaka University has taken a step closer to making inexpensive solar that can deliver the same as more complex and expensive cells.

"Unmodified throw away light energy in the form of reflection, so most solar cells have some kind of antireflective coating," explains first author Daichi Irishika. "To avoid using these extra coatings we fabricated a submicron structure using a simple wet treatment directly into the silicon surfaces to give the cell its own antireflective coating."

Antireflective coatings, similar to those used on reading glasses, can help to get more light into solar cells and boost their electricity output. However, these coatings are expensive to produce, especially for covering large areas.

The Osaka team has previously made low reflection silicon cells using a much cheaper process based on the surface structure chemical transfer (SSCT) method to fabricate so-called black silicon. Chemically treating the front side of silicon cells produces tiny submicron silicon structures, which prevent light reflection and give a black appearance. The team has also developed a method to passivate the submicron silicon structures with huge surface area to prevent the recombination loss by deposition of phosphosilicate glass followed by heat treatment. This method can simultaneously form pn-junction to separate photo-generated electrons and holes, and therefore, it isn't an additional process.

Solar scientists rough up silicon panels to boost light capture
Figure 2. Comparison of low reflectance mechanisms for previous technology and developed technology. Credit: Osaka University

Building on their previous success, the Osaka team turned their attention to the back side of the and created rougher light-trapping microstructures to capture even more infrared light.

Group leader Hikaru Kobayashi says, "Making very high efficiency is important but we should also consider the economics and practicality of any processes used to increase efficiency. The wet processes we have developed are simple yet effective, and our work with black silicon has real-world applications in making cost-effective silicon ."

Explore further: New way to make low-cost solar cell technology

More information: Daichi Irishika et al. Improvement of Conversion Efficiency of Silicon Solar Cells by Submicron-Textured Rear Reflector Obtained by Metal-Assisted Chemical Etching, Solar RRL (2017). DOI: 10.1002/solr.201700061

Related Stories

New way to make low-cost solar cell technology

November 14, 2016

Researchers at ANU have found a new way to fabricate high efficiency semi-transparent perovskite solar cells in a breakthrough that could lead to more efficient and cheaper solar electricity.

New efficiency record for low-cost solar cell

April 4, 2017

Researchers at The Australian National University (ANU) have achieved a new record efficiency for low-cost semi-transparent perovskite solar cells in a breakthrough that could bring down the cost of generating solar electricity.

Efficiency of silicon solar cells climbs past 26 percent

March 21, 2017

(Tech Xplore)—A team of researchers working at Kaneka Corporation has broken the record for silicon-based solar cell efficiency by producing a cell that was tested to be 26.3-percent efficient—an increase of 0.7 percent ...

Toward 'greener,' inexpensive solar cells

September 28, 2016

Solar panels are proliferating across the globe to help reduce the world's dependency on fossil fuels. But conventional panels are not without environmental costs, too. Now scientists are reporting in the Journal of the American ...

Recommended for you

Pushing lithium ion batteries to the next performance level

December 13, 2018

Conventional lithium ion batteries, such as those widely used in smartphones and notebooks, have reached performance limits. Materials chemist Freddy Kleitz from the Faculty of Chemistry of the University of Vienna and international ...

Uber filed paperwork for IPO: report

December 8, 2018

Ride-share company Uber quietly filed paperwork this week for its initial public offering, the Wall Street Journal reported late Friday.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.