For the past decade, solar energy developers have been abuzz over a group of crystalline materials called perovskites because they show promise to enable efficient solar cells that, due to the materials’ printability, could be mass-produced cheaply.
For the entirety of his young career, Colin Bailie, 29, has been focused on this material and its potential for disrupting the $50B silicon solar cell industry. As a Stanford graduate student, Bailie broke ground with his research into combining perovskite with conventional solar materials in order to create tandem devices that can turn more of the spectrum into electricity. Since then, he has developed pathways to improve the longevity and performance of perovskite for use in solar cells. In 2016, Bailie joined Cyclotron Road in Cohort 2, where he’s advancing his technology toward a viable product. In recent months, he recruited solar industry veteran Chris Eberspacher (former CTO at Hanwa and Applied Materials SunFab) as a cofounder. Together, they have landed nearly $1 million in grant funds and other support to get closer to that goal post.
“The basic silicon solar cell is market leading, and it’s really good at absorbing infrared light but it’s not good at absorbing visible light,” Bailie explains. Perovskites, however, can capture visible light. “By combining the two materials — having them work in tandem — you can make a more efficient solar cell than either material on its own.”
In fact, tandem is the moniker used to describe such combined solar cells, and so it follows that Bailie has recently renamed his startup, which was born as Iris PV, to Tandem PV.
Tandem PV’s approach to manufacturing photovoltaic cells is to deposit a metal-halide perovskite solar cell, which is transparent to infrared light, over a silicon-based cell, which then absorbs that infrared energy. It’s important to note that the highest practical efficiency (that is, the ratio of electricity produced based on solar energy collected) of silicon cells is 25 percent, whereas a tandem photovoltaic cell made from perovskite and silicon could reach 30 or even 35 percent. That potential — and the possibility of producing perovskite tandems cheaply — accounts for all the excitement over this new type of solar energy that Tandem PV is pursuing.
Late last year, ARPA-E, the Department of Energy agency focused on advancing new energy technologies, awarded Bailie’s company a $500,000 grant to partner with the National Renewable Energy Lab (NREL)to develop and test a method of processing and depositing perovskites over large areas in a manner that ensures high optical and electronic quality. The goal is to use this to replace a less-scalable production process.
The Department of Energy’s Advanced Manufacturing Office also awarded the startup a $250,000 voucher to work with NREL to explore a different approach for scaling perovskite solar cell production: the use of inkjet printing.
And in early January, Tandem PV landed a $225,000 grant through the National Science Foundation’s Small Business Innovation Research (SBIR)/Small Business Technology Transfer (STTR) program in order to identify opportunities to use perovskite solar cells to power wireless sensors or other devices used indoors to enable Internet of Things applications. Since fluorescent and LED lighting emits only visible light, these cells could help users clear an important hurdle: replacing the batteries needed to power such devices when they’re installed indoors.
This influx of funding has enabled Tandem PV to bring on four new hires: principal chemist Matt Kuchta; principal engineer Dave Pechin; device engineers Jack Love and Alex Sharenko. It also provides Tandem PV with a runway to meet its technology and market goals.
“Over the coming 18 months, we’ll use this funding to help us reach commercial readiness with demonstrations of performance, durability, scalability, and cost,” said Bailie.