Molecular coating boosts organic solar cells

• An electrode coating just one molecule thick can substantially enhance the efficiency of an organic photovoltaic cell, KAUST scientists have actually found. The coating outperforms the leading product currently made use of for this job and may lead the way for enhancements in various other tools that rely upon organic molecules, such as light-emitting diodes and also photodetectors.

Unlike one of the most common photovoltaic cells that use crystalline silicon to harvest light, natural photovoltaic cells (OPVs) rely on a light-absorbing layer of carbon-based molecules. Although OPVs can not yet competing the performance of silicon cells, they could be simpler and less expensive to make at a very large scale using printing strategies.

When light gets in a solar battery, its power releases an adverse electron as well as leaves a positive void, called an opening. Different materials then collect the electrons as well as holes and also direct them to various electrodes to produce an electric existing. In OPVs, a material called PEDOT: PSS is extensively used to alleviate the transfer of generated openings into an electrode; however, PEDOT: PSS is costly, acidic as well as can deteriorate the cell's performance over time.

The KAUST group has now developed a much better alternative to PEDOT: PSS. They utilize a much thinner coating of a hole-transporting molecule called Br-2PACz, which binds to an indium tin oxide (ITO) electrode to form a single-molecule layer. The organic cell making use of Br-2PACz achieved a power conversion effectiveness of 18.4 percent, whereas an equal cell utilizing PEDOT: PSS got to only 17.5 percent.

" We were extremely shocked undoubtedly by the efficiency enhancement," states Yuanbao Lin, Ph.D. trainee as well as participant of the group. "Our company believe Br-2PACz has the possible to replace PEDOT: PSS as a result of its inexpensive and also high performance."

Br-2PACz boosted the cell's effectiveness in numerous means. Compared with its opponent, it caused less electric resistance, enhanced opening transportation and permitted extra light to radiate through to the taking in layer. Br-2PACz likewise enhanced the framework of the light-absorbing layer itself, an effect that might be associated with the coating process.

The coating could also enhance the recyclability of the solar cell. The scientists found that the ITO electrode could be removed from the cell, stripped of its coating and then recycled as if it was new.

In contrast, PEDOT: PSS roughens the surface area of the ITO to make sure that it chokes up if reused in an additional cell. "We expect this will have a dramatic impact on both the business economics of OPVs and also the atmosphere," claims Thomas Anthopoulos, that led the study.