Mapping Photocurrent in LOPV devices

Spatially Resolved Photocurrent Microscopy (SRPM) is a technique used to directly probe local areas of photovoltaic cells. A sample is scanned across a focused light beam and the resulting photo-current is recorded. This is accomplished using a confocal microscope which has been modified for these measurements. This instrument allows for simultaneous fluorescence and photocurrent imaging. Using this experimental setup and simulation work, we expect that the spatially resolved photocurrent should be high in the space charge regions (SCR) and low in the recombination zone.

Laser Beam Induced Current

Members Involved:

Marlene Gutierrez

Monroe Griffin

Photocurrent vs. Position Profile

These images show Light Beam Induced Current (LBIC) in a Lateral Organic Photovoltaic (LOPV) device. Regions of high photocurrent exist near the electrodes and regions of low photocurrent exist in the center of the LOPV device. Increasing the voltage bias increases the size of the Space Charge Region (SCR). In addition, a white light bias also increases the size of the SCR. We use SRPM to measure the SCRs and recombination zone.