Finding junction partners for CsPbI3 in a two-terminal tandem solar cell: A theoretical prospect.

Screening ideal partner materials for the CsPbI 3 perovskite is crucial for developing all-inorganic perovskite-based tandem solar cells. Here, we quantize the performance of all-inorganic tandem solar cells combining the CsPbI 3 perovskite with c-Si, GaAs, CdTe, CIGS, and CsSnI 3 , by analyzing the measured spectral efficiencies and developing macroscopic continuum device (MCD) model. Firstly, we integrate the MCD model and the principles of detailed balance (Shockley-Queisser limit model, SQM) to investigate the top CsPbI 3 solar cell with varying thickness and the rear sub-cell with different bandgaps. Without considering the nonradiative recombination and absorptivity in the rear sub-cell, an efficiency of over 32% can be reached by selecting the low bandgap materials (E gap ~ 1.1 eV) as the rear sub-cell. Furthermore, after the simulation by MCD model that takes the charge recombination, absorptivity and optimal thicknesses for both sub-cells in tandem architectures into account, CIGS is found to be one of the best junction partners for CsPbI 3. During the simulations, a unique bisection search algorithm is used to guarantee that the continuity of electric potential near the junction layer and the current matching of sub-cells in the tandem solar cells. As a result, a CsPbI 3 (470 nm)/CIGS(2000 nm) tandem solar cell with the best-modeled efficiency of 24.40% can be achieved, which is affirmed by a recent experimental result. Finally, we simulate the corresponding bifacial tandem photovoltaic device, and the optimal modeled efficiency can be further enhanced to 25.58%. Image 1 • Tandem solar cells combining CsPbI3 with c-Si, GaAs, CdTe, CIGS, and CsSnI3 are theoretically analyzed with two models. • A bisection search algorithm is used to guarantee the continuity of electric potential and the current matching. • Hybrid MCD/SQM and complete MCD models are used to screen the parameters and simulate the photovoltaic performances. • An efficiency of >32% can be achieved by using the materials with E g around 1.1 eV as the rear cell with the MCD/SQM model. • With MCD simulations, the CsPbI 3 (470 nm)/ CIGS(2000 nm) tandem solar cell demonstrates the best-modeled efficiency of 24.40%. [ABSTRACT FROM AUTHOR]