Organic, polymer-based photovoltaic cells have always been much more cost-efficient to produce, however they have also been much less efficient in their energy conversion than their silicon-based counterparts. That is, until now.

"We've shown that impure domains if made sufficiently small can also lead to improved performances in polymer-based organic photovoltaic cells," says Harald Ade, a physicist at North Carolina State University, who led this research. "There seems to be a happy medium, a sweet-spot of sorts, between purity and domain size that should be much easier to achieve than ultra-high purity."

Ade’s group is the first to actually measure the acceptor domains, finding the “sweet-spot” for size and purity in order to build a more efficient solar cell, allowing researchers to test device variables better.

"In showing for the first time just how pure and how large the acceptor domains in organic solar devices actually are, as well as what the interface with the donor domain looks like, we've demonstrated that the impact of solvents and additives on device performance can be dramatic and can be systematically studied," Ade says. "In the future, our technique should help advance the rational design of polymer-based organic photovoltaic films."

Read the whole article here