Plastic Solar Cells - A Promising Breakthrough
by: Jakob Jelling
by: Jakob Jelling
What are plastic solar cells? They are a scientific breakthrough that promises to replace expensive and bulky
traditional silicon-based solar cells with affordable and lightweight new plastic solar material. The only problem is the lower efficiency of plastic solar material that cannot yet compete with traditional silicon solar material.
Researchers from all over the world are constantly producing yet more powerful new polymer (plastic) cells. The efficiency of plastic solar is rising by around 1% per year. If these rates of development continue at this pace, it may take as little as several years for polymer solar to move silicon solar from its dominant market position. Today, there are polymer cells that have around a 6% efficiency rate (rate of converting the absorbed sunlight into electricity). Approximately a 10% efficiency rate would be enough for the plastic materials to start competing with silicon and its 15-18% efficiency rate.
Let's review the design of a plastic solar cell. Polymer cells have a specific layered design: glass at the top, then a transparent electrode, then two polymer layers, then a layer of titanium oxide, and finally an aluminum electrode. How can we make plastic solar materials more efficient? It's all about the polymers in their active layer that cannot absorb specific types of light. One of the ways to boost the efficiency of plastic solar material would be to use several different polymer layers capable of picking up varying bands of light. Yet, layering would increase the manufacturing costs and thus defeat the whole purpose of cheap polymer solar.
Here are the main pros of polymer solar cells: they are made of lightweight, thin, and flexible film; their fabrication costs are around three times less than that of silicon technology; their technology is very simple; they could be sprayed onto various surfaces; they are translucent; they are simple to work with; they have minuscule installation costs due to super-easy installation. Flexible plastic can be rolled up, wrapped around surfaces, and even painted onto different structures. Plastic solar could replace roof tiling or be incorporated into buildings' facades, placed on automobiles, etc. Also, they would eliminate the need to reinforce the support of the mounting base (for instance, on the roof), since there would be no additional weight whatsoever. And finally, their cost is three times lower than silicon. Even though silicon is an abundant natural semiconductor, it does not mean that it makes for cheap cells, as silicon cells are expensive to fabricate.
And now let's take a look at their cons: plastic solar is three times less efficient than silicon solar; plastic has a very short lifetime (around three years) due to organic carbon in it.
Homeowners and businesses around the globe are looking forward to the emergence of powerful plastic solar cells. Already now these cells are used in some portable electronic devices due to their beneficial features. Now plastic solar cells are in their “coming soon stage”, but the days of their triumph may be closer
than we expect. Relatively soon we may see tremendously efficient and long-lasting plastic solar technology.