Recent progress made by ASU electrical engineers in developing nanowires for use in alternative energy sources could lead to the increased efficiency and feasibility of these energy sources.
The research, conducted by ASU professor Cun-Zheng Ning and other faculty, was started more than five years ago when he worked at NASA.
Ning said he decided to focus on the materials used to construct nanowires because of their importance to the efficiency of energy sources.
“Semiconductor materials are behind almost all of the technologically-important applications, such as solar panels, light-emitting diodes that are used in the lighting of ASU parking garages or traffic lights anywhere across the country, and tiny lasers used at the supermarket checkout,” Ning said in an e-mail.
However, these materials are limited individually, in that they can only absorb or emit certain parts of the electromagnetic spectrum, he said. This means they do not absorb all of the light that hits them from the sun.
“One critical parameter of semiconductors for all these applications is the so-called energy gap or bandgap. Bandgap of a semiconductor determines what color of light a semiconductor emits or how and what color of sunlight will be absorbed,” Ning said.
Given this data, the idea is to make an alloy, or mixture of two different substances, of two different semiconductor materials, which will allow it to absorb more kinds of light, he said.
The wider the bandgap, the more energy can be absorbed, in the case of solar panels, or emitted, in the case of LEDs. The more energy that is able to be absorbed or produced, the more efficient that energy source is, and alternative energy becomes more economically feasible.
“The main reason that our unique alloy nanowires could potentially improve the efficiency of photovoltaic (PV) cells is the fact that we can produce a wide range of bandgaps that match the entire spectrum of sun light,” Ning said.
The research is part of a larger, University-wide effort to become a leader in the research and use of alternative energy sources.
“What ASU does can have an influence on the world, both in how students observe and learn how a campus could be run,” said Bonny Bentzin, ASU’s assistant director of Sustainability Initiatives in the Office of the President.
What is done in the lab can eventually have an effect on the way the University operates, she said.
“I would like to see us eventually demonstrate the work we are doing in the lab on campus, but obviously if they produce the technology that then goes to market, that’s something we can use on campus as well,” she said.
The research comes on the heels of other innovations in the area, including separate work to improve solar panels.
Reach the reporter at dana.sheaff@asu.edu
