Barium di-silicide (
BaSi2) material has attracted noteworthy interest in photovoltaics,
thanks to its stability, abundant nature, and excellent production feasibility. In this current
work, a two-terminal (2T) monolithic all-BaSi2 tandem solar cell is proposed and explored
through extensive TCAD simulation. A BaSi2
bottom sub-cell with a bandgap of 1.3 eV,
and a Ba(CxSi1−x)2 top sub-cell with a tunable bandgap are employed in the design. It was
found that a bandgap of 1.8 eV, which corresponds to x = 0.78, is the optimum choice to
obtain the maximum initial power conversion efficiency (η) of 30%. Then, the tandem
performance is optimized by investigating the impact of doping and the thickness of both
absorber layers. Further, the current matching point is monitored whilst altering the thickness
of the top cell resulting in η = 32.83%%, and a short-circuit current density (Jsc) of
16.47 mA/cm2. Additionally, we have explored the influence of the defect density in the
absorbers, and the work function of contacts on the performance parameters. All TCAD
simulations are accomplished using the Silvaco Atlas package under AM1.5G illumination.