Oregon State University researchers have discovered a way to tap the sun not only as a source of power, but also to directly produce the materials needed for solar devices.
The team of chemical engineers believes that the process could reduce the cost of solar energy, speed production processes, use environmentally benign materials, and make the sun almost a “one-stop shop” for energy production.
The findings were just published in RSC Advances, a journal of the Royal Society of Chemistry, in work supported by the National Science Foundation.
The work is based on the use of a “continuous flow” microreactor to produce nanoparticle inks that make solar cells by printing. Existing approaches based mostly on batch operations are more time-consuming and costly, the researchers say.
In this process, simulated sunlight is focused on the solar microreactor to rapidly heat it, while allowing precise control of temperature to aid the quality of the finished product. The light in these experiments was produced artificially, but the process could be done with direct sunlight, and at a fraction of the cost of current approaches, according to the researchers.
This system can synthesize solar energy materials “in minutes” compared to other processes that might take 30 minutes to two hours, according to Chih-Hung Chang, a professor of chemical engineering at Oregon State University, and lead author on the study.
In these experiments, the solar materials were made with copper indium diselenide, but to lower material costs it might also be possible to use a compound such as copper zinc tin sulfide, Chang said. And to make the process something that could work 24 hours a day, sunlight might initially be used to create molten salts that could later be used as an energy source for the manufacturing. This could provide more precise control of the processing temperature needed to create the solar energy materials.