PV cell for outer space targets 40% efficiency

PV cell for outer space targets 40% efficiency

The Optoelectronics Research Lab at the University of Arkansas received a $1 million grant to research, fabricate, and test a photovoltaic cell with 40% efficiency for use in outer space. NASA and the university will provide the funding for the research, with administrative support coming from the Arkansas State University.

The performance increase is significant over what’s available now. The theoretical maximum efficiency of silicon solar cells is about 29%, so researchers have to get creative to improve on silicon products. To increase the efficiency, some researchers are making cells with different materials that can capture energy not only from visible light, but from the infrared and ultraviolet spectrum as well. The highest-quality cells are costly and reserved for use in space and concentrating solar collectors. Such cells, used by NASA, have an efficiency of about 23%. This new research from the University of Arkansas aims at improving that efficiency to 40%.

High-efficiency photovoltaic cells from University of Arkansas will use the ultraviolet effect on nanocrystals to improve its efficiency.

The researchers have decided to use two approaches to pursue their goal of high efficiency PV cells. The first is to use copper, indium, gallium, selenium (CIGS) variant semiconductor material (CuInSe2 and CuInGaSe2) to grow nanocrystals. The nanocrystals are then either converted into thin films or combined with titanium dioxide or zinc oxide nanotubes to create the solar cells. After fabrication of the cells, the researchers will test and evaluate their performance.

The second approach uses a molecular beam epitaxy method to deposit the nanocrystals, to create quantum dots of indium arsenide, which are nanosized particles of semiconductor material. In an attempt to enhance the cells’ efficiency, the researchers will use these molecules that bind to a central atom to couple metallic nanoparticals to the nanocrystals or quantum dots. The researchers will then test the resultant photovoltaic cells. They expect to determine if a plasmonic effect that traps sunlight, occurs. This plasmonic effect can also increase the energy conversion efficiency, maybe to about 40%.

Cells resultant from the research could be used to power electrical equipment on NASA satellites. For more information, see newswire.uark.edu/article.aspx?id=16826.

Paul O’Shea