High-performance ultrathin Cu(In,Ga)Se₂ solar cell optimized by silvaco tools

In this work, we investigated the influence of the cell pitch, opening width, Ga/(In + Ga) ratio, absorber layer thickness, and doping on ultrathin CIGS solar cell performance by using ATLAS tools. First, to validate our investigated solar cell, we discuss and compare our simulation models with fabricated cells with/without rear-passivation Al₂O₃/Cu(In_1−xGa_x)Se₂. We observed significant improvements in cell performance while using a thin film Al₂O₃ for the rear-passivation with a high density of negative charge, where the rear side contact recombination losses can then be reduced. The simulation results follow the experimental trends, highlighting the beneficial effects of rear-passivation in the ultrathin absorber layer. However, poor passivation was observed when a rear-passivation layer is with a high density of positive charge or in high contact resistance at Ag/CIGS interface. Consequently, the optimum combination led to achieving 14.30% with 10¹⁶ cm⁻³, 2.5 µm, and 250 nm for absorber doping, cell pitch, and cell width, respectively. The obtained results from the simulated cells were compared to the recently published research work.