Carrier control in Sn–Pb perovskites via 2D cation engineering for all-perovskite tandem solar cells with improved efficiency and stability

Carbazole-Based Hole Transport Polymer for Methylammonium-Free Tin–Lead Perovskite Solar Cells with Enhanced Efficiency and Stability

“…11−14 However, one serious concern for Sn−Pb PSCs is their poorer stability than their pure lead-based counterparts. 15 As the most commonly used HTM in Sn−Pb PSCs, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PE-DOT:PSS) has advantages of good wetting for reproducible perovskite solution deposition, and appropriate energy levels for efficient hole extraction from Sn−Pb perovskites. 16 However, the PEDOT:PSS HTM accelerates perovskite degradation due to its corrosive acidic characteristics and hygroscopic properties.…”

“…Sn–Pb-alloyed perovskites have a lower bandgap of 1.21 eV when the Sn/Pb ratio is ≈1, which is the optimal composition to build perovskite-perovskite tandems . The narrow bandgap Sn–Pb PSCs can be paired with the wide bandgap perovskite to form all-perovskite tandem solar cells, whose PCEs have already been demonstrated to surpass that of the top-performing single-junction PSCs. − However, one serious concern for Sn–Pb PSCs is their poorer stability than their pure lead-based counterparts …”

A Roadmap for Efficient and Stable All-Perovskite Tandem Solar Cells from a Chemistry Perspective

“…61 Recently, the same group reported that mixing an appropriate proportion of PEAI and GuaSCN further improves the optoelectronic properties of Sn−Pb perovskites through the formation of quasi-2D structure (PEA) 2 GuaPb 2 I 7 . 62 The addition of this quasi-2D structure reduces the dark carrier density and enhances the bulk carrier lifetime, boosting the PCE of the NBG perovskite solar cells over 22% (Figure 3d). Sargent and co-workers found that PEAI-dissolved antisolvent can passivate defects both at the surface and within the perovskite films yet avoid the excess formation of the 2D phase perovskites to block the charge carrier transport.…”

“…Copyright 2017 and 2021 Wiley, respectively. Panels (c–e) reproduced with permission from refs , , and , respectively. Copyright 2019, 2022, and 2022 Springer Nature, respectively.…”

Present status and future prospects for monolithic all-perovskite tandem solar cells

“…The CSA strategy improved the performance of both NBG and WBG subcells, leading to the highest PCE of 25.05% for tandem cells. Based on the previous report of GASCN engineering, Zhu's group [20] further found that by using the mixed additive with phenethylammonium iodide (PEAI) and GASCN to form a quasi-two-dimensional (2D) structure, the optoelectronic quality of Pb-Sn perovskites can be further improved. They obtained 22.1%-efficient singlejunction Pb-Sn perovskite cells and 25.5%-efficient all-perovskite 2-T tandems.…”