A polymer-based technique could lead to production of highly efficient solar cells. A team from IK4-Ikerlan and the University of the Basque Country used polymers that absorb light at different wavelengths to produce solar cells with a tandem structure. “Until now, that structuring has been done mechanically or by means of laser, but with the risk of damaging the substrate,” said Dr. Ikerne Etxebarria-Zubizarreta, a researcher in chemical engineering at UPV/EHU and IK4-Ikerlan. “However, in this research we have developed a new automatic structuring technique. This technique involves transforming the features of the surface of the substrate.” Two polymer solar cells are connected in series, powering a toy. Courtesy of IK4-Ikerlan. The researchers also analyzed the capacity that new materials, such as polymers, have to absorb solar energy, in addition to what the maximum size of the cells should be. “We found that in cells of up to approximately 6 cm2, the power was in direct proportion to their surface area,” Etxebarria-Zubizarreta said. “On larger surface areas, however, the performance of the cells falls considerably.” She added that to manufacture cells with a large surface area, it is necessary to build modules to which cells with a smaller surface will be connected, in series or in parallel. The production of cells manufactured using polymers or other new materials are expected to be more cost-effective, the researchers said, since those polymers are produced in the laboratory. For more information, visit www.ehu.es.