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Guest Article: School of Illinois Scientists Indicate Us Little Known Techniques to Produce More Effective Pv panels
Despite the fact that silicon is actually the market normal semiconductor in almost all electric units, which includes the solar cells that photovoltaic panels utilize to convert sunshine into power, it is not really the most effective product on the market. For instance, the semiconductor gallium arsenide and associated compound semiconductors offer practically two times the efficiency as silicon in photo voltaic devices, yet they are rarely used in utility-scale applications mainly because of their high construction value.
University of Illinois teachers J. Rogers and X. Li investigated lower-cost techniques to manufacture thin films of gallium arsenide that also allowed versatility in the types of devices they could be included into.
If you can minimize substantially the price of gallium arsenide and other compound semiconductors, then you could increase their range of applications. Usually, gallium arsenide is transferred in a individual thin layer on a smaller wafer. Either the preferred device is made specifically on the wafer, or the semiconductor-coated wafer is break up into chips of the ideal size. The Illinois group decided to deposit multiple levels of the material on a one wafer, creating a layered, "pancake" stack of gallium arsenide thin films.
If you grow 10 layers in one growth, you simply have to load the wafer one time. If you do this in ten growths, loading and unloading with temp ramp-up and ramp-down get a lot of time. If you consider exactly what is needed for each growth -- the machine, the planning, the time, the workers -- the overhead saving this solution gives is a substantial expense reduction.
Next the scientists separately peel off the layers and move them. To complete this, the stacks swap layers of aluminum arsenide with the gallium arsenide. Bathing the stacks in a formula of acid and an oxidizing agent dissolves the layers of aluminum arsenide, freeing the individual thin sheets of gallium arsenide. A soft stamp-like device selects up the layers, just one at a time from the top down, for shift to another substrate -- glass, plastic material or silicon, based on the application. Next the wafer can be used again for another growth.
By doing this it's possible to generate significantly more material a lot more fast and much more cost efficiently. This process could create bulk quantities of material, as compared to merely the thin single-layer manner in which it is usually grown.
Freeing the material from the wafer also starts the possibility of flexible, thin-film electronics produced with gallium arsenide or some other high-speed semiconductors. To make devices which can conform but still maintain high efficiency, which is significant.
In a paper written and published online May 20 in the magazine Nature, the group explains its procedures and demonstrates three types of products making use of gallium arsenide chips made in multilayer stacks: light devices, high-speed transistors and solar cells. The creators also provide a comprehensive cost comparability.
Another benefit associated with the multilayer technique is the release from area constraints, particularly important for solar cells. As the levels are removed from the stack, they could be laid out side-by-side on another substrate in order to produce a much greater surface area, whereas the typical single-layer process confines area to the dimension of the wafer.
For solar panels, you want large area coverage to catch as much sunlight as achievable. In an extreme situation we may develop adequate layers to have ten times the area of the standard.
Next, the group plans to explore more possible unit applications and other semiconductor materials that could adapt to multilayer growth.
About the Author - Shannon Combs shares knowledge for the residential solar power generators blog site, her personal hobby website centered on recommendations to assist home owners to conserve energy with sun power.