Researchers at Sandia National Laboratories are looking into using metal-organic framework (MOF) materials, which are likened to chemists’ tinkertoys, as part of developing a new generation of photovoltaic devices. In this instance the researchers are investigating combining MOFs with dye-sensitized solar cells (DSSC). To further their research the lab was recently awarded a $1.2 million award from the U.S. Department of Energy’s SunShot Initiative.
“A lot of people are working with DSSCs, but we think our expertise with MOFs gives us a tool that others don’t have,” said Erik Spoerke, a materials scientist at Sandia, who focusses on solar devices. The DSSC devices usually consist of specially designed dyes that can absorb certain spectra of light that are paired with titanium dioxide or other semiconductors to create PV devices.
“Our hypothesis is that we can put a thin layer of MOF on top of the titanium dioxide, thus enabling us to order the dye in exactly the way we want it,” said Sandia senior scientist Mark Allendorf. He likened MOFs to tinker toys for chemists since they can easily and quickly be assembled into new structures.
As such, the researchers believe they can incorporate multiple layers of dyes in the MOF, which absorb more of the spectrum of light. By ordering the dyes and locking them into MOF’s crystalline structure it should help avoid some ways in which the efficiency has been sapped in the past.
“Essentially, we believe MOFs can help to more effectively organize the electronic and nano-structure of the molecules in the solar cell,” said Spoerke. “This can go a long way toward improving the efficiency and stability of these assembled devices.”
Allendorf added that: “If you don’t have everything in the DSSC dependent on everything else, it’s a lot easier to optimize your photovoltaic device in the most flexible and effective way.” The MOF allows them some flexibility in the department.
“It becomes almost modular in terms of the cell’s components, all of which contribute to making electricity out of sunlight more efficiently,” said Spoerke.Tweet