Getting Started with the Ossila Solar Cell I-V Test System

Current-Voltage Measurements (I-V curves)

Current-voltage measurements (I-V curves) are the primary measurement for characterizing solar cells. Here, the current flowing through the device is measured at different voltages whilst it is under illumination. There are several key properties that can be extracted from the I-V curve of a solar.

The short-circuit current density (J_sc) is the photogenerated current density of the solar cell when there is no driving voltage, and can be extracted from the intercept with the y-axis.

The open-circuit voltage (V_oc) is the voltage at which the applied voltage cancels out the built-in electric field, and can be extracted from the intercept with the x-axis.

The fill factor (FF) is the ratio of the actual output power of the device to its power if there were no parasitic resistances. This can be calculated by dividing the maximum power output of the device by the product of the J_sc and the V_oc (the potential maximum power).

Finally, the power conversion efficiency (PCE), the ratio of incident light power (P_in) to output electrical power (P_out), can be calculated.

For a more in-depth explanation about the characterization of solar cells, see our guide on solar cell theory and measurement.

Power Conversion Efficiency (PCE) Equation

The Power Conversion Efficiency (PCE) of a solar cell can be calculated from the ratio of incident light power (P_in) to output electrical power (P_out) using the following equation:

Here, as above, J_sc is the short-circuit current density, V_oc is the open-circuit voltage, and FF is the fill factor.