BUFFALO, N.Y. – Most Americans want the U.S. to place more
emphasis on developing solar power, recent polls suggest.
A major impediment, however, is the cost to manufacture, install
and maintain solar panels. Simply put, most people and businesses
cannot afford to place them on their rooftops.
Fortunately, that is changing because researchers such as
Qiaoqiang Gan, University at Buffalo assistant professor of
electrical engineering, are helping develop a new generation of
photovoltaic cells that produce more power and cost less to
manufacture than what’s available today.
One of the more promising efforts, which Gan is working on,
involves the use of plasmonic-enhanced organic photovoltaic
materials. These devices don’t match traditional solar cells
in terms of energy production but they are less expensive and -
because they are made (or processed) in liquid form - can be
applied to a greater variety of surfaces.
Gan detailed the progress of plasmonic-enhanced organic
photovoltaic materials in the May 7 edition of the journal Advanced
Materials. Co-authors include Filbert J. Bartoli, professor of
electrical and computer engineering at Lehigh University, and Zakya
Kafafi of the National Science Foundation.
The paper, which included an image of a plasmonic-enhanced
organic photovoltaic device on the journal’s front page, is
available at: http://bit.ly/11gzlQm.
Currently, solar power is produced with either thick
polycrystalline silicon wafers or thin-film solar cells made up of
inorganic materials such as amorphous silicon or cadmium telluride.
Both are expensive to manufacture, Gan said.
His research involves thin-film solar cells, too, but unlike
what’s on the market he is using organic materials such as
polymers and small molecules that are carbon-based and less
“Compared with their inorganic counterparts, organic
photovoltaics can be fabricated over large areas on rigid or
flexible substrates potentially becoming as inexpensive as
paint,” Gan said.
The reference to paint does not include a price point but rather
the idea that photovoltaic cells could one day be applied to
surfaces as easily as paint is to walls, he said.
There are drawbacks to organic photovoltaic cells. They have to
be thin due to their relatively poor electronic conductive
properties. Because they are thin and, thus, without sufficient
material to absorb light, it limits their optical absorption and
leads to insufficient power conversion efficiency.
Their power conversion efficiency needs to be 10 percent or more
to compete in the market, Gan said.
To achieve that benchmark, Gan and other researchers are
incorporating metal nanoparticles and/or patterned plasmonic
nanostructures into organic photovoltaic cells. Plasmons are
electromagnetic waves and free electrons that can be used to
oscillate back and forth across the interface of metals and
Recent material studies suggest they are succeeding, he said.
Gan and the paper’s co-authors argue that, because of these
breakthroughs, there should be a renewed focus on how nanomaterials
and plasmonic strategies can create more efficient and affordable
thin-film organic solar cells.
Gan is continuing his research by collaborating with several
researchers at UB including: Alexander N. Cartwright, professor of
electrical engineering and biomedical engineering and UB vice
president for research and economic development; Mark T. Swihart,
UB professor of chemical and biological engineering and director of
the university’s Strategic Strength in Integrated
Nanostructured Systems; and Hao Zeng, associate professor of
Gan is a member of UB’s electrical engineering optics and
photonics research group, which includes Cartwright, professors
Edward Furlani and Pao-Lo Liu, and Natalia Litchinitser, associate
The group carries out research in nanphotonics, biophotonics,
hybrid inorganic/organic materials and devices, nonlinear and fiber
optics, metamaterials, nanoplasmonics, optofluidics,
microelectromechanical systems (MEMS), biomedical
microelectromechanical systems (BioMEMs), biosensing and quantum