Most solar cells are rigid. They must be deployed in stiff, often heavy, fixed panels, limiting their applications. So researchers have been trying to make solar photovoltaics in different shapes, sizes and materials. Stanford researchers have succeeded in developing the world’s first peel-and-stick thin-film solar cells. They are flexible, decal-like solar panels that can be peeled off like band-aids and stuck to virtually any surface, from papers to window panes.

Peel-and-Stick Solar Technology

DIY Solar Panel using Peel-and-Stick Thin-Film Solar Cells

DIY Solar Panel using Peel-and-Stick Thin-Film Solar Cells

Unlike standard thin-film solar cells, the peel-and-stick version from Stanford university does not require any direct fabrication on the final carrier substrate. This is a far more dramatic development than it may initially seem. All the challenges associated with putting solar cells on unconventional materials are avoided with the new process, vastly expanding the potential applications of solar technology.

Thin-film solar photovoltaic cells are traditionally fixed on rigid silicon and glass substrates, greatly limiting their uses. And the development of thin-film solar cells promised to inject some flexibility into the technology. Nonconventional substrates are difficult to use for photovoltaics because they typically have irregular surfaces and they don’t do well with the thermal and chemical processing necessary to produce today’s solar cells.

Peel-and-Stick process gives thin-film solar cells flexibility and attachment potential we’ve never seen before, and also reduces their general cost and weight.

Making of Peel-and-Stick Thin-Film Solar Cells

The new process involves a unique silicon, silicon dioxide and metal “sandwich.” First, a 300-nanometer film of nickel (Ni) is deposited on a silicon/silicon dioxide (Si/SiO2) wafer. Thin-film solar cells are then deposited on the nickel layer utilizing standard fabrication techniques, and covered with a layer of protective polymer. A thermal release tape is then attached to the top of the thin-film solar cells to augment their transfer off of the production wafer and onto a new substrate. The solar cell is now ready to peel from the wafer.

Tests have demonstrated that the peel-and-stick process reliably leaves the thin-film solar cells wholly intact and functional. There’s also no waste. The silicon wafer is typically undamaged and clean after removal of the solar cells, and can be reused.

Applications of Peel-and-Stick Thin-Film Solar Cells

Peel-and-Stick Solar Stickers

Demonstrations of the Stanford Peel-and-Stick Thin-Film Solar process on various applications.

Now you can put the solar cell/panel stickers on helmets, cell phones, convex windows, portable electronic devices, curved roofs, clothing – virtually anything. You can convert any surface to a solar panel. Obviously, a lot of new products – from ‘smart’ clothing to new aerospace systems – might be possible by combining both thin-film electronics and thin-film solar cells.

Advantages of Peel-and-Stick Thin-Film Solar Cell Technology

While others have been successful in fabricating thin-film solar cells on flexible substrates before, those efforts have required modifications of existing processes or materials. The main contribution of this project work is the solar cell arrays are built so without modifying any existing processes, facilities or materials, making them viable commercially. And the researchers demonstrated Peel-and-Stick solar-panel process on a more diverse array of substrates than ever before.

Moreover, peel-and-stick technology isn’t necessarily restricted to thin-film solar cells. The researchers believe the process can also be applied to thin-film electronics, including printed circuits and ultra thin transistors and LCDs.