An international research team has explained for the first time that silicon nanowires that have been randomly grown can considerably enhance the power-generating capabilities of solar cells by trapping sunlight radiating in from different angles and capturing a wide spectrum of light waves.
The research team, which includes researchers from Massachusetts Institute of Technology, Taiwan -based Institute of Electro-Optical Engineering, Beijing University of Science and Technology, City University of New York and New York University, described its process in the article ‘Graded index and randomly oriented core-shell silicon nanowires for broadband and wide angle antireflection’ published in AIP Advances, a journal of the American Institute of Physics.
The nanowires that are sheathed in a silicon oxide shell function as an antireflective coating over the normally shimmering silicon wafer. The scraggly tangle traps color light ranging between red and violet and the haphazard arrangement of the nanowires allows constant absorption of light by the coating even though the angle of the sun’s rays keep varying throughout the day. The tangled, efficient, antireflective coating was fabricated by scientists through the vaporization of silicon powder and by subsequently depositing it above a silicon wafer. This cost-effective process can be used for large production operations. The research team intends to continue its research to fabricate more ordered structures in order to test whether a random arrangement is really more ideal.
Source: http://www.aip.org