Numerical Simulation of Tandem Using ZnS as a Buffer Layer Cu I<sub>(1-<i>x</i>) </sub>Ca<sub><i>x</i></sub>Se<sub>2</sub>/CuGaSe<sub>2</sub>

In the global context of diversification usable energy sources, use renewable energies, in particular solar photovoltaic energy, is becoming increasingly important. As such, development a new generation cells based on CIGS material promising. Indeed, efficiency these has exceeded 20% recent years. Thus, our work consists modeling tandem cell Cu(In,Ga)Se2 (CGS/CIGS). The goal to optimize its physical and geometrical parameters order obtain better conversion compared other research works past. We used AMPS-1D software for simulation. When we realize tandem, least efficient (CGS) imposes current shape J-V characteristic tandem. obtained theoretical 39.30% which significantly higher than efficiencies past by researchers with short circuit 34.60 mA/cm2, an open voltage 1.74 V form factor 65.20%. simulation also showed that high defect density strongly impacts performance