Designing CIGS solar cells with front-side point contacts

In this work we show how 2D numerical simulations can be used to design and optimize front-side point contacts in surface-passivated CIGS cells. Detailed analysis of the combinations of passivation thickness, point contact size and pitch can help identifying solutions able to boost the performance of otherwise surface-limited cells: efficiencies close to those of cells with ideal (i.e., trap-free) CdS/CIGS interface can be achieved by the optimization of point contact features in the low nm range. The effect of varying the CIGS and CdS doping densities on the cell performance has also been analyzed.