Ultralight solar cells - New from MIT

How to use solar cell technology to reach as many applicable surfaces as possible and replace heavy solar energy collecting equipment? Engineers at MIT now have a solution for placing solar cells in unimaginable places.

Now any surface can be a source of energy

This solar cells are so thin and lightweight that they can be applied onto the wings of drones in order to extend their flying range. Also, they envisioned a possible purpose for such cells by placing them on tent wings and tarps which can be set during disaster recovery operations or by integrating them onto the sails of a boat.

They see the undoubted advantage of this lightweight solar technology in the ability to install it on existing environments with minimal installation effort.

Efficiency

Engineers describe them as one-hundredth the weight of conventional solar panels and generate 18 times more energy per kilogram. They are made from semiconductor inks using a printing process that can be scaled up to large-area production in the future.

Vladimir Bulović, the Fariborz Maseeh Chair in Emerging Technology, leader of the Organic and Nanostructured Electronics Laboratory (ONE Lab), director of MIT.nano. says: "The metrics used to evaluate a new solar cell technology are typically limited to their power conversion efficiency and their cost in dollars-per-watt. Just as important is integrability -- the ease with which the new technology can be adapted". Then he continues: "We strive to accelerate solar adoption, given the present urgent need to deploy new carbon-free sources of energy".

Testing revealed how this kind of solar device could generate 730 watts of power per kilogram when freestanding and about 370 watts-per-kilogram if deployed on the high-strength Dyneema fabric. Engineers have established how it is about 18 times more power-per-kilogram than conventional solar cells.

How it works?

To produce the solar cells, engineers use nanomaterials that are in the form of a printable electronic inks. The whole process must take place in MIT.nano clean room where they coat the solar cell structure using a slot-die coater, which deposits layers of the electronic materials onto a prepared surface that is only 3 microns thick and can be separated. Then, to complete the solar module, an electrode is placed on the structure using screen printing, which they explain is a technique similar to how designs are added to screen-printed T-shirts.

By producing solar modules using this printing technique, they made it possible to detach the printed module with a thickness of 15 microns from the plastic substrate in the next step, thus creating an ultra-light solar device. They identified fabrics as the optimal solution, as they provide mechanical resilience and flexibility with little added weight. "The lightweight solar fabrics enable integrability, providing impetus for the current work," says Vladimir Bulović, the Fariborz Maseeh Chair in Emerging Technology, leader of the Organic and Nanostructured Electronics Laboratory (ONE Lab), director of MIT.nano.