Current Students: Jonathan DeWitt (PSM-PV) , Zhaoning Song (PhD), Jon Stone (UGrad)
Previous Students: Meghan Mapes (PSM-PV), John Royston (MS), Ryan Zeller (PSM-PV)
Associated Faculty: Randy J. Ellingson, Michael J. Heben, Adam B. Phillips
A laser beam induced current or voltage measurement scans a laser beam across a photovoltaic
device as a pin-point light source. The current or voltage is measured and graphed
as a function of the laser beam’s position. The image shown on the left side is an
example of a cadmium telluride solar cell illuminated with 532 nm laser radiation.
In our lab, images can be taken with 1064, 532, or 355 nm excitation, displaying responses
from different layers in the device. The images show pin holes and defects and can
be used to give an idea of deposition non-uniformities. The individual devices shown
in the image are ~ 3 mm x 3 mm, and where scribed using the same apparatus.