Tag Archives: nanotechnology

Wonderful Things: High Efficiency Solar Cell

 

Small but remarkably powerful… Objects come in all shapes and sizes and in one of our newest galleries, Atmosphere, you can find a small but amazingly powerful object, the high efficiency solar cell. 

 

High Efficiency Solar Cell

Tiny but huge: the high efficiency solar cell

The Sun provides the Earth with more energy every hour than humans use in a year! Therefore, with fossil fuels running out, the heat and light from the Sun has potential to be a great replacement energy source. We just need to be able to capture it. So how do we do this?

The answer is with solar cells, which are electrical devices made using layers of silicon that convert light into electricity. Incredibly, the first solar cell was created in 1883, although this was very inefficient, converting only 1% of light into electricity. Scientists largely ignored them until the 1950s when those working on the space program needed a way to power satellites in orbit. Solar cells were the best option for this and since then, much work has gone into improving their efficiency. 

Solar cells are now found in many places, you may have seen them on rooftops or on your calculator. But how do they work? In a nutshell, they absorb light into the layers of silicon, which is treated so that one side is more attractive to electrons than the other. The light energy knocks electrons loose and allows them to jump between the layers of silicon, thus creating a current. They have real potential as an alternative energy source; however, at present they can only convert about 15% of light energy into electricity.     

Will they get any better? Research is currently underway at Imperial College London into how we can improve their efficiency. Using nanotechnology, scientists are able to artificially alter the properties of the materials in the cells. They can then ‘tune’ them so that they can absorb and convert more of the available light into electricity. By using nano-structures researchers have increased the efficiency of the solar cell to 40% with potential for even more! So it just goes to show that sometimes, the best things really do come in small packages!

Do you think that solar cells are the best alternative energy source for the UK? Or do you think that there are other renewable energy sources that could be more effective? 

What would you power with solar cells if you could?

The high efficiency solar cell can be found in the Atmosphere gallery on the 2nd floor of the Wellcome Wing. 

-Kate Davis 

 

Think tiny

Nanotechnology is a hot topic, and there is a wealth of information online- we have just found a useful site that covers the main things, from the definition of nanotechnology to some of its applications and risks: 10 things you should know about nanotechnology. You can get your students to explore it for research prior to a discussion on the topic… but it’s quite text-heavy, so if you need to lighten things up, why not use Punk Science’s Nanotechnology Song to hook your students in first!

Artists interpretation of carbon nanotubules

And if you want to do some demonstrations or activities in the classroom, this site contains some cool experiments you or your students can do quickly, with instructional videos. Mmmm, liquid crystals…

Films, films galore!

When running a classroom discussion, it’s important to kick off with a starter that is engaging as well as informative, something that can help your students form an opinion on the issue and give them some knowledge to bring to the discussion.

Stimulus materials can be anything from relevant objects, news clippings, films, even witty songs. Planning a discussion around nanotechnology? Show your students this great new Punk Science film – Nanotechnology song!  And in Healthy Living, Punk Science explore the neurotransmitters that make us happy (and raise questions about fair testing!)

And if you want to get a few ideas for making your science pop, check out How to Punk your science… Having perfectly messy, artfully tousled hair is not a prerequisite.

Finally, we invited a group of scientists to try out our Mystery Boxes activity- see what they thought about it in this film.

Enjoy!

Punk Science are (from left) Dan Hope and Jon Milton