China's non-toxic organic solar cells achieve record 20% efficiency

Chinese researchers from Shenzhen University of Technology have developed a new type of organic solar cell (OSC) that achieves a record efficiency of around 20% while using non-toxic, environmentally friendly materials. Unlike previous OSCs that relied on harmful solvents like chloroform, these cells use toluene, a safer solvent. The team enhanced the internal morphology of the solar cells by adding two isomeric chemical additives, ODBC and PDBC, which help the materials inside the cell align more precisely. This improved alignment facilitates better sunlight absorption and charge transfer, resulting in higher efficiency and greater stability suitable for mass production. The additives work by slowing the drying process, allowing the solar cell materials to crystallize in a more orderly fashion, which boosts performance and reduces energy loss over time. The researchers optimized the placement of these additives within the solar cell layers, notably in the acceptor layer, to maximize their beneficial effects. Their best configuration achieved a certified efficiency of 19.7% using the green solvent to