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].

Graphical AbstractA comparison of r-e CuGaSe2 cell with another one showing the different current components under illumination. j1, j2 and j3 relate to interface recombination, recombination in the depletion region and shunt; respectively.Figure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights► Distinctive features of the record-efficiency CuGaSe2 (r-e) cell are pointed out. ► Interface recombination is weaker in the r-e cell. ► Concentrations of acceptors, donors and interface states are lower in the r-e cell.