Researchers at the Vienna University of Technology have combined two semiconductor materials, each only three atomic layers thick. Adding one semiconducting layer of the photoactive crystal tungsten diselenide to a layer of molybdenum disulphide, and “creating a designer-material that may be used in future low-cost solar cells.” Having worked with graphene, that two-dimensional, atom-thick material that promises much for structures, batteries and solar cells, Thomas Mueuller, assistant professor of photonics, and his team “acquired the necessary know-how to handle, analyze and improve ultra-thin layers by working with graphene.” The team applied their lessons learned with graphene to combining two ultra-thin semiconductor layers and are now studying their optoelectronic properties. Mueller explains, ““Quite often, two-dimensional crystals have electronic properties that are completely different from those of thicker layers of the same material.” In their present study, the Tungsten diselenide, a semiconductor consisting of three atomic layers; one layer of tungsten sandwiched between two layers of selenium atoms. Mueller adds, “We had …
Solar Cells a Few Atoms Thick
Researchers at the Vienna University of Technology have come up with a way to create one-atom thick, flexible, semi-transparent solar cells. Instead of the graphene often touted as a means toward such an end, however, the scientists have turned to atom-thick layers of tungsten diselenide for their wonder material. Experiments show that ultrathin layers of tungsten and selenium may have properties that would make them applicable even to electric aircraft use – if they can capture a significant amount of energy – or at least as much as thin-film silicon cells can. Graphene has been a popular favorite since its Russian “discoverers” were awarded the Nobel Prize in physics in 2010. One of the strongest materials, graphene can manage stresses and strains better than most and has “great opto-electronic properties.” Its atomic-scale thinness allows it to transform optical signals into electronic pulses extremely quickly. Despite these outstanding characteristics, “The electronic states are not very practical for creating photovoltaics,” according to …