Electrical engineers performing research in the field of photovoltaics (PV) are largely concerned with finding ways to boost PV cell efficiency and, ultimately, drive down PV costs. Records in PV cell efficiency rates are being broken in labs all the time, but researchers at the University of Pittsburgh are predicting that greater progress can with low-cost “plastic” or organic cells by focusing at the molecular level.
The inner workings of PV cells are invisible to the naked eye. According to Guangyoung Li, assistant professor of electrical and computer engineering at University of Pittsburgh, even “traditional force” microscopy does not provide the resolution needed to properly examine the electrical surface potential of cells. Li’s solution is to use an established method called Kelvin probe force microscopy (KPFM) to better understand the electrical functions of solar cells. While KPFM is not a new technology, the team, with funding from the National Science Foundation, plans to use it in a novel way to help develop more efficient organic solar cells.
Currently, low-cost plastic solar cells have an efficiency of only about 8 percent. Li hopes the instrument will enable the development of such cells with an efficiency of 10 percent or higher. Li notes this research could not only lead to the development of more efficient low-cost solar panels, but is also the “ideal platform” to train young scientists, and educate the greater community, including K-12 students, teachers, industry leaders, and the general public.
“In the future, I can imagine this new, efficient material anywhere—on buildings, roofs, you name it,” said Li. “You could charge your laptop, cellphone, or iPod simply by having a charger on you and stepping into sunlight.”