Ever felt thwarted with your typical solar cells with only limited power supply and limited applications? Researchers at Stanford University have been working on to shake off such frustration and finally come up with a solution.
Scientists at Stanford University in collaboration with the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) have developed Peel-and-Stick versions of solar cells that can charge your cell phones, change the tint on windows and any other battery-powered products.
“These cells have been used before for nanowire based electronics, but the Stanford-NREL partnership has conducted the first successful demonstration using actual thin film solar cells,” said Qi Wang, principal scientist at NREL.
As the name says “Peel-and-Stick”, these cells can be attached to almost any surface from papers to window panes and then peeled off like band-aids. But, to acquire these properties, a silicon substrate is used from which one-micron thick thin-film solar cells are removed and later fabricated by dipping them in water at room temperature and heat at about 90 degree celsius.
“NREL’s cells could be made easily on Stanford’s peel off substrate. NREL’s amorphous silicon cells were fabricated on nickel-coated Si/SiO2 wafers. A thermal release tape attached to the top of the solar cell serves as a temporary transfer holder. An optional transparent protection layer is spin-casted in between the thermal tape and the solar cell to prevent contamination when the device is dipped in water. The result is a thin strip much like a bumper sticker: the user can peel off the handler and apply the solar cell directly to a surface. The cells’ ability to adhere to a universal substrate is unusual; most thin-film cells must be affixed to a special substrate. The peel-and-stick approach allows the use of flexible polymer substrates and high processing temperatures. The resulting flexible, lightweight, and transparent devices then can be integrated onto curved surfaces such as military helmets and portable electronics, transistors and sensors.” NREL said in a post on their official site.
Figure 1: Procedures of the peel-and-stick process.
Figure 2: TFSCs at different stages of the peel-and-stick process.
Figure 3: Comparisons of the TFSC performances before and after the peel-and-stick process.
Figure 4: Mechanical flexibility of the transferred TFSCs.