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 [1]. 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 [2].