Nanostructures improve solar cell efficiency

May 26, 2011 by Annette Ostrand

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 surfaces of silicon solar cells. By creating different nanostructures on the surfaces, the energy harvesting properties of solar cells can be improved.

Within the EU-funded research project N2P ( To Production) researchers work on nanostructured surfaces of solar cells. At the Fraunhofer Institute in Dresden, Germany, researchers have focused on the development of plasma chemical etching (AP-PCE) processes. This technology is as an alternative to the wet chemical processing approach, used in the . The advantages of AP-PCE over the etching technology based on wet chemical processing are, for example, reduced chemical waste, cost efficiency and reduced handling. AP-PCE is used for modifying solar wafers’ surfaces down to the nanoscale. The researchers have achieved a one-percent improvement in solar cell efficiency, from 16 to 17 percent, by making the rear surface very smooth.

Within the N2P research project scientists at the Ecole Polytechnique Federale de Lausanne (EPFL) in Neuchatel, Switzerland, are instead working on improving different solar cells, the thin film silicon solar cells. Currently, these solar cells can only harvest about seven percent of the sunlight, which is about 40 percent less efficient compared to conventional wafer silicon cells. However, the thin film solar cells are cheaper and more eco-friendly because their production demands less time, material and energy. The researchers in Switzerland are changing the top glass structure of the solar cell, by depositing a layer of nanosized crystals from a transparent conductive oxide (TCO) onto the glass. This layer gives a high scattering effect and the light beam generates more electrons when it travels a longer distance though the cell, which enhances the cell’s light absorption. The researchers have managed to achieve a 30 percent increase in efficiency in comparison with standard thin film solar cells.

Another process that could increase the efficiency of thin film , through changing the surface structures, includes ultrafast pulsed laser irradiation. Researchers at Singapore Institute of Manufacturing Technology have shown that this irradiation makes a nanospike pattern on the silicon surface which reduces reflection of the light from the surface. More light will therefore be absorbed.

New processes which create nanostructured surfaces are improving solar cell efficiency substantially. With lower manufacturing costs in the future the interest in solar cell investments may increase impressively.

Explore further: Making graphene in your kitchen

add to favorites email to friend print save as pdf

Related Stories

Nano-tuned solar cells

May 18, 2011

Solar cells that are more effective and cost less in production: Within the EU-project N2P (Nano to Product) researchers developed nano tuned surfaces to gain both.

Recommended for you

Making graphene in your kitchen

14 hours ago

Graphene has been touted as a wonder material—the world's thinnest substance, but super-strong. Now scientists say it is so easy to make you could produce some in your kitchen.

Thinnest feasible nano-membrane produced

Apr 17, 2014

A new nano-membrane made out of the 'super material' graphene is extremely light and breathable. Not only can this open the door to a new generation of functional waterproof clothing, but also to ultra-rapid filtration. The ...

Wiring up carbon-based electronics

Apr 17, 2014

Carbon-based nanostructures such as nanotubes, graphene sheets, and nanoribbons are unique building blocks showing versatile nanomechanical and nanoelectronic properties. These materials which are ordered ...

Making 'bucky-balls' in spin-out's sights

Apr 16, 2014

(Phys.org) —A new Oxford spin-out firm is targeting the difficult challenge of manufacturing fullerenes, known as 'bucky-balls' because of their spherical shape, a type of carbon nanomaterial which, like ...

User comments : 0

More news stories

Making graphene in your kitchen

Graphene has been touted as a wonder material—the world's thinnest substance, but super-strong. Now scientists say it is so easy to make you could produce some in your kitchen.

Finnish inventor rethinks design of the axe

(Phys.org) —Finnish inventor Heikki Kärnä is the man behind the Vipukirves Leveraxe, which is a precision tool for splitting firewood. He designed the tool to make the job easier and more efficient, with ...