Current-voltage analysis of the record-efficiency CuGaSe2 solar cell: Application of the current separation method and the interface recombination model

Current-voltage (j-V) characteristics of the record-efficiency CuGaSe2 solar cell measured under several illumination levels are analyzed using a two-diode equation for a more accurate description of cell behavior. The contribution of each diode to the total cell j-V characteristic under illumination was estimated using the current separation method presented recently. This is performed in an effort to identify the distinctive features of this record-efficiency cell which have led to the up-to-date highest open circuit voltage of Voc = 946 mV and fill factor of FF = 66.5% for CuGaSe2 solar cells. Furthermore, the interface recombination component of the cell current under illumination is quantitatively discussed applying the interface recombination model presented earlier. (author)