Solvent Engineering Improves Efficiency of Lead-Free Tin-Based Hybrid Perovskite Solar Cells beyond 9%

Abstract

Here, we report on the effect of different antisolvent dripping on film morphology and charge recombination of mixed formamidinium–methylammonium tin iodide (FA0.75MA0.25SnI3) as a light absorber in perovskite solar cells. N,N-dimethyl methanamide (DMF) and dimethyl sulfoxide (DMSO) were used as the mixed solvent in the perovskite precursors together with tin fluoride (SnF2) as an additive. Diethyl ether (DE), toluene (TL), and chlorobenzene (CB) were employed as antisolvents for comparison. Our results show that CB as an antisolvent leads to a dense and uniform Sn-based perovskite film. The maximum power conversion efficiency of our Sn-based perovskite solar cell achieves 9.06% (9.02%) under forward (reverse) voltage scan under AM 1.5G 100 mW/cm2 illumination. The encapsulated cells show good long-term stability with ∼75% of their initial efficiency retained over a period of 30 days of storage. Our work suggests the promising potential to further improve the performance of Pb-free Sn-based perovskite solar cells.

Two‐Dimensional Halide Perovskites in Solar Cells: 2D or not 2D?

“…Although it is known that 2D tin‐halide perovskites are oxygen sensitive, it has also been shown that they are more stable towards oxygen and humidity than their 3D homologous . Today, the best PCE for a 2D tin halide perovskite is 5.94 %, which is comparable to the first 2D PSC reported and no too far from the best lead‐free 3D PSC (9.06 %) …”

“…[106,108] Today,t he best PCE for a2 Dt in halide perovskite is 5.94 %, which is comparable to the first 2D PSC reported [88] and no too far from the best lead-free 3D PSC (9.06 %). [109] Other attempts to replace lead were 2D copper halide-based perovskites. The first report was by Cortecchia et al, [110] who reported the use of MA 2 CuBr 4Àx Cl x -type materials in solar cell devices ( Figure 11).…”

Tin Halide Perovskites: Progress and Challenges

“…Although the Pb halide perovskites still hold the supreme position regarding materials and device characteristics and performance, Sn halide perovskites have also benefited in numerous ways from the partial or complete substitution of Pb with Sn. Sn halide perovskites are adaptable to various preparation techniques which may include solution and vapor deposition methods . These techniques usually follow a low temperature processing pathway.…”

Lead‐Free Tin‐Based Perovskite Solar Cells: Strategies Toward High Performance

“…Up till now, both the commercial and the homemade SnI 2 have been used for high‐efficiency Sn‐based PSCs. However, homemade SnI 2 is not accessible for all the researchers for lack of either equipment or synthetic skills.…”