Little Known Methods to Create More Productive Solar panels
by Shannon Combs
(http://www.residentialsolarpanels.org)
Thin Film Solar
Although silicon is the industry normal semiconductor in almost all electronic devices, which includes the pv cells that photo voltaic panels employ to transform sun rays into power, it is not really the most effective product readily available.
For instance, the semiconductor gallium arsenide and related ingredient semiconductors offer nearly twice the effectiveness as silicon in solar units, but they are rarely employed in utility-scale applications mainly because of their high construction price.
U. of Illinois. ( http://illinois.edu/ ) teachers J. Rogers and X. Li investigated lower-cost techniques to manufacture thin films of gallium arsenide that also granted flexibility in the types of units they can be included into.
If you may minimize substantially the cost of gallium arsenide and some other compound semiconductors, then you could expand their own range of applications.
Generally, gallium arsenide is placed in a single thin layer on a smaller wafer. Either the needed device is made specifically on the wafer, or the semiconductor-coated wafer is break up into chips of the ideal size. The Illinois group chose to deposit several levels of the material on a simple wafer, creating a layered, “pancake” stack of gallium arsenide thin films.
If you increase 10 layers in 1 growth, you simply have to fill the wafer a single time. If you do this in ten growths, loading and unloading with temp ramp-up as well as ramp-down take a lot of time. If you consider exactly what is needed for every growth – the machine, the research, the time, the people – the overhead saving this method provides is a significant price decrease.
After that the experts independently peel off the levels and transfer them. To achieve this, the stacks swap levels of aluminum arsenide with the gallium arsenide.
Bathing the stacks in a formula of acid and an oxidizing agent dissolves the levels of aluminum arsenide, freeing the individual small sheets of gallium arsenide. A soft stamp-like system selects up the layers, just one at a time from the top down, for shift to one other substrate – glass, plastic material or silicon, depending on the application. Next the wafer may be reused for one more growth.
By performing this it's possible to create significantly more material a lot more fast and more cost effectively. This process could produce bulk amounts of material, as compared to simply the thin single-layer method in which it is typically grown.
Freeing the material from the wafer also opens the probability of flexible, thin-film electronics produced with gallium arsenide or other high-speed semiconductors. To make units which can conform but still maintain higher efficiency, that is considerable.
In a paper released online May 20 in the magazine Nature (http://www.nature.com), the team describes its techniques and demonstrates three types of units making use of gallium arsenide chips made in multilayer stacks: light products, high-speed transistors and photo voltaic cells. The authors also offer a comprehensive price evaluation.
Another advantage associated with the multilayer method is the release from area constraints, especially important for photo voltaic cells. As the levels are removed from the stack, they may be laid out side-by-side on another substrate to produce a much greater surface area, whereas the standard single-layer process restricts area to the dimension of the wafer.
For photovoltaics, you need big area coverage to catch as much sunlight as achievable. In an extreme case we could increase adequate layers to have 10 times the area of the conventional.
After that, the group programs to explore more potential item applications and other semiconductor resources which could adapt to multilayer growth.
About the Publisher of this article - Shannon Combs is currently writing for the
residential solar power options site, her personal hobby weblog focused on tips to help home owners to save energy with sun power.