Instead of rigid, cumbersome flat solar panels, you could soon be powering your home and electronics with a sticker. Engineers at Stanford have successfully fabricated thin, flexible solar cells that are able to be peeled and attached to almost any surface. The new technology is described in the December 20th issue of Scientific Reports and details how the team of scientists led by Xiaolin Zheng and Chi Hwan Lee achieved such a remarkable breakthrough. In addition to being dynamic, the peel-and-stick process also reduces cost and weight, making the cells an attractive alternative to their uncompromising relatives.
The team at Stanford were able to create their cell by making a silicon dioxide “sandwich”. First, a 300-nanometer film of nickel is placed on a silicon dioxide wafer. Thin film solar cells are then added on the nickel layer, and coated with a protective polymer. Then, a layer of thermal release tape is added to the top of the cells to help with their transfer from the hard wafer. To remove the newly formed cell, the wafer is submerged in water at room temperature while the thermal release tape is peeled back, allowing water to come into contact with the silicon dioxide and nickel. Now the cell is free from its hard substrate but still attached to the tape. The tape is heated at 90°C for several seconds, and can afterwards be attached to any surface. In the final step, the thermal release tape is removed, leaving the cell stuck to its new home.
Amazingly, the team was able to accomplish their new process without sacrificing efficiency or making any great modifications to existing methods or materials, making them already commercially viable. There is also no waste, as the silicon wafer remains clean and undamaged and can be reused after the cells are removed. They are also lightweight and use low-cost. Combined with thin film electronics, the new cells could help power a whole new set of wearable technologies that incorporate printed circuitry and LCD displays.