Researchers from Aalto University in Finland and Université de Montréal in Canada are exploring if all of our devices, like phones, cars and smart clothing, could one day be charged completely with flexible solar cells.
Solar energy seems like am ideal power source, but so far it has been hard to fully harness all of the sun’s energy to power all of our devices. The research team has studied how to create solar cell technology that operates efficiently, while also being simple for mass production and commercialization.
Solar cells like this one could soon be responsible for charging your phone. Source: Wikimedia / CC BY-SA 3.0
The team confirmed that solar cells can be mass produced for our everyday devices, but there are quite a few things that need to be developed, changed and improved before becoming a complete solution.
First, how are solar cells made? Smaller solar cells for handheld devices need to be made by roll-to-roll processing. In the roll-to-roll process, solar cells are created on rolls of flexible plastic or metal foils. Inkjet printing is perfect for the roll-to-roll process because it allows for the insertion of dye and electronic components on to the flexible plastics or metal foils.
The hardest part of creating handheld flexible solar cells is mastering the flexible cell encapsulation. If a solar cell has inefficient cell encapsulation there are two things that could happen. The first is that the liquid electrolyte may leak out of the cell. The second issue would be that impurities could seep into the device. If either or both of these issues happen, the lifetime of the flexible solar cell would be significantly decreased.
"Flexible solar cells are usually made on metals or plastics, and both come with perils: a metal may corrode, and plastics may allow water and other impurities to permeate," said Dr. Kati Miettunen, a project manager at Aalto's Department of Bioproducts and Biosystems.
In order to overcome these issues, the researchers found that the substrates that are used to create solar cells need to be joined together. There are currently some techniques that can do this for flat panel displays and other electronics, like glass-frit bonding, but don’t currently work for solar cells. The solar cell industry needs to work on a way to solve this problem before the next step can be taken towards mass-producing flexible solar cells.
One option could be using biomaterials or hybrid materials made from wood pulp as substrates in the solar cells. These materials have a natural ability to filter out any impurities so they could be the key to solving this problem.
While there are still a few other issues that need to be taken care of before mass production, flexible solar cells to charge your cell phone or car are closer than ever.
The paper detailing all the solar cell research was published in WIREs Energy and Environment journal.
