The analysis of the current-voltage characteristics of a solar cell (Si, GaAs and Triple junction) and their array is one of the most important diagnostic methods used to characterize the solar cell and array. The current-voltage equation that models the solar cell by an equivalent electrical circuit, contains several parameters related to physical phenomena occurring in the device. Changes in the parameter values may reveal important information about the effects of environmental conditions e.g. radiation effect on space solar cells, or the manufacturing processes on the performance of solar cells. Different curve fitting algorithms are used to extract the solar cell and array parameters
from the measurement data and used for the performance analysis of photovoltaic systems.