Scientists have proposed capturing of solar energy with the help of “solar energy funnel” that would be able to confine a broader spectrum of solar energy.
This research has been published online in the journal Nature Photonics.
“We’re trying to use elastic strains to produce unprecedented properties,” Ju Li, an MIT professor and corresponding author of the paper, said in a statement.
Scientists in this study used strain-engineered molybdenum disulfide (MoS2) monolayer to develop “funnels” to capture a broad range of solar spectrum. It is a natural semiconductor with sufficient “bandgap” properties to enable it to be used in solar cells. Under strain this material’s bandgap may change responding to different colors of light.
Acctually the “funnel” is a metaphor. In this funnel-like structure electrons and holes are moved to the center of the structure with the help of electronic forces rather than gravity. A microscopic needle like structure puts pressure for elastic strain that is increased towards the center of the thin material of the stretched sheet that works like a funnel. The different amount of strain changes the atomic structure that is sufficient to “tune” different sections according to different wavelengths of light that is not only the visible light but also the invisible spectrum of sunlight’s energy and according to researchers “an optoelectronic material with a spatially varying bandgap that is tunable is highly desirable for use in photovoltaics, photocatalysis and photodetection.”
This research has been supported by the U.S. National Science Foundation, the U.S. Air Force Office of Scientific Research, and the National Natural Science Foundation of China.
Ji Feng, Xiaofeng Qian, Cheng-Wei Huang and Ju Li, (2012). Strain-engineered artificial atom as a broad-spectrum solar energy funnel. Nature Photonics, doi:10.1038/nphoton.2012.285