Simulation approach for studying the performances of original superstrate CIGS thin films solar cells

In this work, we report on the performances of superstrate Cu(In,Ga)Se 2 (CIGS) thin film solar cells with an alternative SLG/SnO 2 :F/CIGS/In 2 Se 3 /Zn structure using AMPS-1D (Analysis of Microelectronic and Photonic structures) device simulator. An inverted surface layer, n-type CIGS layer, is inserted between the In 2 Se 3 buffer and CIGS absorber layers and the SnO 2 :F layer is just a transparent conducting oxide (TCO). The simulation has been carried out by lighting through SnO 2 :F. The obtained results show that the existence of so-called ‘ordered defect compound’ (ODC) layer in such a structure is the critical factor responsible for the optimization of the performances. Photovoltaic parameters were determined using the current density-voltage ( J–V) curve. An optimal absorber and ODC layer thickness has been estimated, that improve significantly the devices efficiency exceeding 15% AM1.5 G. The variation of carrier density in In 2 Se 3 layer has an influence on the superstrate CIGS cells performances. Moreover, the quantum efficiency (Q.E.) characteristics display a maximum value of about 80% in the visible range.