Thin, efficient solar cells
New Research from Air Force Develops Efficient Solar Panels
According to research from the Air Force Research Laboratory, a new development for a comprehensive and flexible material used in wearable electronics is being developed from thin solar panel material.
The Research for Thin Solar Cells
Photovoltaics, or solar cells, are being used on some of our generations most advanced up-in-coming applications; however, integration into Air Force technology and solutions has been difficult due to the density of the material. As it turns out, the material that is being used to make the microscopic solar cells is actually very thick and non-durable. There have been numerous attempts to make the material thinner, lighter and more advantageous for production; however, these measures have greatly reduced the original properties of the material making them impractical for today’s technologies and wearable solutions.
To address this issue, research and testing needed to be administered to find an appropriate solution for the flexible material that could also harvest solar energy efficiently. After that, it was important for the researchers to make the solar cell material thinner and able to convert energy to electricity. They produced these results, by using a solar material called inorganic-organic hybrid perovskite. This material allowed the team of researchers to make the thin transparent cells. However, along the way, the researchers ran into more difficult problems when it came to the formation of the thin layer of solar cell.
Dr. Santanu Bag, project scientist, explained the challenges of thinning the material while retaining as much efficiency as possible. “One of the main issues of creating thin layers of perovskite is the formation of surface defects in the form of pinholes,” said Bag. “The pinholes generate a high frequency of shunting pathways that prevent the charge from traveling through the absorber layer. This condition results in even greater device inefficiency than is caused by the film thinness itself.”
In order to find a solution to the problem, the team of researchers were able to expose the material to thiourea, an organic compound that acts as a “molecular glue” and allows the pinholes to absorb through the light-absorbing layer of the cell. Fortunately, the team was able to develop a pinhole-free thin perovskite material that can be used on electronic applications and create sources for energy production. These materials make for great semiconductors, which represent a type of materials that are used in modern computing and lighting devices. Potential applications for this solar cell include photodetectors, field-effect transistors, and light-emitting diodes. The scientists in the research group found that new sensors for electronic technologies can be a potential application that the material will help produce.
A patent application for this invention has been filed jointly by Bag and Dr. Michael F. Durstock, AFRL group lead, with funding from the Air Force Office of Scientific Research.
Bag said the next steps for the team are to simplify and scale-up the process of growing the perovskite films by introducing additive manufacturing into the fabrication process. The current spin-coating process is labor intensive, slow, and costly. Additive manufacturing provides a faster and less-costly way of producing the solar cells.
Source and top image: Air Force Research Laboratory, www.printedelectronicsworld.com