Upper Subcell Properties Effects on 2T-Perovskite/PERT C-Si Tandem Solar Cell Performance

In this article, perovskite and two-terminal perovskite/PERC tandem solar cells have been numerically performed and optimized using Silvaco TCAD tools. The investigated planar perovskite and PERT C-Si models have been performed accordingly to match the fabricated structures for tandem configuration. These two cells have been simulated individually and they have revealed an efficiency of up to 20% and 22.9% for perovskite and PERT, respectively. The two-terminal tandem model is then developed by comprising the top cell with the bottom cell by transparent contact that connects the two subcells in series electrically. The influence of defect density in the perovskite layer and at electron transport layer (ETL)/absorber and absorber/hole transport layer (HTL) interfaces on perovskite and tandem cell characteristics is analyzed. It has been found that using MgF2 on the outer surface of the front module glass can effectively enhance photon absorption in the tandem device over the entire wavelength range. By adjusting the perovskite thickness through the current matching process and minimizing bulk and interface defect traps, we can be able to achieve 22% and 26% efficiencies for wide bandgap perovskite and tandem solar cells, respectively. These approaches allow us to gain a better understanding of the defect density effect on the performance of the structures.

keywords: Efficiency, modeling, perovskite, PERT, tandem cell