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Interfacial engineering of perovskite films has been the main strategies in improving the efficiency and stability of perovskite solar cells (PSCs). In this study, three new donor‐acceptor (D–A)‐type interfacial dipole (DAID) molecules with hole‐transporting and different anchoring units are designed and employed in PSCs. The formation of interface dipoles by the DAID molecules on the perovskite film can efficiently modulate the energy level alignment, improve charge extraction, and reduce non‐radiative recombination. Among the three DAID molecules, TPA‐BAM with amide group exhibits the best chemical and optoelectrical properties, achieving a champion PCE of 25.29 % with the enhanced open‐circuit voltage of 1.174 V and fill factor of 84.34 %, due to the reduced defect density and improved interfacial hole extraction. Meanwhile, the operational stability of the unencapsulated device has been significantly improved. Our study provides a prospect for rationalized screening of interfacial dipole materials for efficient and stable PSCs. [ABSTRACT FROM AUTHOR]

In the pursuit of highly efficient perovskite solar cells, spiro‐OMeTAD has demonstrated recorded power conversion efficiencies (PCEs), however, the stability issue remains one of the bottlenecks constraining its commercial development. In this study, we successfully synthesize a novel self‐polymerized spiro‐type interfacial molecule, termed v‐spiro. The linearly arranged molecule exhibits stronger intermolecular interactions and higher intrinsic hole mobility compared to spiro‐OMeTAD. Importantly, the vinyl groups in v‐spiro enable in situ polymerization, forming a polymeric protective layer on the perovskite film surface, which proves highly effective in suppressing moisture degradation and ion migration. Utilizing these advantages, poly‐v‐spiro‐based device achieves an outstanding efficiency of 24.54 %, with an enhanced open‐circuit voltage of 1.173 V and a fill factor of 81.11 %, owing to the reduced defect density, energy level alignment and efficient interfacial hole extraction. Furthermore, the operational stability of unencapsulated devices is significantly enhanced, maintaining initial efficiencies above 90 % even after 2000 hours under approximately 60 % humidity or 1250 hours under continuous AM 1.5G sunlight exposure. This work presents a comprehensive approach to achieving both high efficiency and long‐term stability in PSCs through innovative interfacial design. [ABSTRACT FROM AUTHOR]

The perovskite material has received much attention due to its excellent photoelectric properties. However, the toxicity of Pb has always affected the wide application of perovskite materials. Herein, we proposed to replace Pb ions with the same divalent ions Ba and dope them into the CsPbBr3 perovskite nanocrystals' (PNCs) lattice to reduce the content of Pb elements. In this work, we have successfully prepared a series of CsPb1−xBaxBr3 PNCs (x = 0, 0.1, 0.2, 0.3, and 0.4) and CsPbBr3 PNCs (Ba-doped concentration = x = 0, 0.05, 0.10, 0.15, and 0.20); the best among them were CsPb0.7Ba0.3Br3 PNCs and CsPbBr3 (Ba = 0.1) PNCs, respectively. Compared with CsPbBr3 PNCs, the photoluminescence (PL) intensity of CsPb0.7Ba0.3Br3 PNCs and CsPbBr3 (Ba = 0.1) PNCs has been improved to different degrees. It was worth mentioning that after the addition of a Ba element, the photoluminescent quantum yield (PLQY) of CsPb0.7Ba0.3Br3 PNCs and CsPbBr3 (Ba = 0.1) PNCs was increased to 81% and 65%, respectively. It was due to the high PLQY of CsPb0.7Ba0.3Br3 PNCs that the selected CIE color coordinate monochromatic light encompassed 119.0% of NTSC color gamut. [ABSTRACT FROM AUTHOR]

[Display omitted] • The PLQY of CsPbBr 3 /Cs 4 PbBr 6 @PDMS achieve to 71%. • CsPbBr 3 /Cs 4 PbBr 6 @PDMS composite was studied for the first time and exhibit excellent optical properties. • The stabilit ies of CsPbBr 3 against heat, water and UV light have been greatly improved. • Under the excitation of blue chip, the color coordinate is extremely close to the standard of white light color coordinate. • The as-prepared film with the color gamut that could reach to 127% of NTSC 1953 and 95% of Rec. 2020 and applied in LCD successfully. All-inorganic perovskites have been considered next-generation color converters in the backlit due to their shining optical properties. However, structural instability severely limits their pragmatic applications. Here, CsPbBr 3 /Cs 4 PbBr 6 microcrystals (MCs) were successfully embedded in polydimethylsiloxane (PDMS) films by a facile two-step method. As-prepared PDMS films containing CsPbBr 3 /Cs 4 PbBr 6 MCs (CsPbBr 3 /Cs 4 PbBr 6 @PDMS) obtain high brightness and excellent stability. Meaningfully, the PDMS films not only serve as a double protective matrix that can be used to improve the stability of CsPbBr 3 /Cs 4 PbBr 6 MCs, but also a flexible substrate with high transparency that allows the CsPbBr 3 /Cs 4 PbBr 6 @PDMS films to be used as color conversion materials for backlit displays. To our surprise, when PDMS is coated with CsPbBr 3 /Cs 4 PbBr 6 MCs, the water, thermal and photostability are greatly improved, while the photoluminescence intensity only lost by 10%. Furthermore, by mixing CsPbBr 3 /Cs 4 PbBr 6 MCs with K 2 SiF 6 :Mn4+ phosphors in PDMS, a monolithic film with high performance was obtained. Its color gamut can reach 127% of the NTSC 1953 standard and 95% of the REC. 2020 standard, exhibiting the bright prospects in the backlit display field. [ABSTRACT FROM AUTHOR]