I-V Characterization of Photovoltaic Cells and Panels
Solar or photovoltaic (PV) cells are devices that absorb photons from a light source and then release electrons, causing an electric current to flow when the cell is connected to a load. Solar panels are just a collection of solar cells connected in series and parallel that provide more power than just a single, smaller cell.
Researchers and manufacturers of PV cells and panels strive to achieve the highest possible efficiency with minimal losses.
As a result, electrical characterization of the cell as well as PV materials is performed as part of research and development and during the manufacturing process. The current-voltage (I-V) characterization of the cell is performed to derive important parameters about the cell’s performance, including its maximum current (Imax) and voltage (Vmax), open circuit voltage (Voc), short circuit current (ISC), and its efficiency (η).
These I-V characteristics can easily be generated using a Keithley Model 2450 or Model 2460 SourceMeter SMU Instrument, which can source and measure both current and voltage. Because both SourceMeter instruments have fourquadrant source capability, they can sink the cell current as a function of an applied voltage.