Large-area, pinhole-free CH₃NH₃PbI₃perovskite thin films were successfully fabricated on 5 cm × 5 cm flexible indium tin oxide coated polyethylene naphthalate (ITO-PEN) substrates through a sequential evaporation/spin-coating deposition method in this research. The influence of the rate-controlled evaporation of PbI₂films on the quality of the perovskite layer and the final performance of the planar-structured perovskite solar cells were investigated. An ultrafast evaporation rate of 20 Å s⁻¹was found to be most beneficial for the conversion of PbI₂to CH₃NH₃PbI₃perovskite. Based on this high-quality CH₃NH₃PbI₃film, a resultant flexible perovskite solar sub-module (active area of 16 cm²) with a power conversion efficiency of more than 8% and a 1.2 cm²flexible perovskite solar cell with a power conversion efficiency of 12.7% were obtained.

Two-terminal (2-T) perovskite (PVK)/CuIn(Ga)Se₂ (CIGS) tandem solar cells (TSCs) have been considered as an ideal tandem cell because of their best bandgap matching regarding to Shockley–Queisser (S–Q) limits. However, the nature of the irregular rough morphology of commercial CIGS prevents people from improving tandem device performances. In this paper, D-homoserine lactone hydrochloride is proven to improve coverage of PVK materials on irregular rough CIGS surfaces and also passivate bulk defects by modulating the growth of PVK crystals. In addition, the minority carriers near the PVK/C60 interface and the incompletely passivated trap states caused interface recombination. A surface reconstruction with 2-thiopheneethylammonium iodide and N,N-dimethylformamide assisted passivates the defect sites located at the surface and grain boundaries. Meanwhile, LiF is used to create this field effect, repelling hole carriers away from the PVK and C60 interface and thus reducing recombination. As a result, a 2-T PVK/CIGS tandem yielded a power conversion efficiency of 24.6% (0.16 cm²), one of the highest results for 2-T PVK/CIGS TSCs to our knowledge. This validation underscores the potential of our methodology in achieving superior performance in PVK/CIGS tandem solar cells.

In this study, a novel ionically crosslinked gel polymer electrolyte (PADA gel electrolyte) with a transmittance of more than 97% was successfully fabricated and applied in electrochromic devices (ECDs) as an ion transport layer. The PADA gel-based ECDs (PECDs) exhibited the large optical modulation of 61% at 660 nm, the high coloration efficiency of 78.7 cm² C⁻¹, and a good memory effect. The shortest colored time (t_c) and bleached time (t_b) of the PECD were 7.5 s and 8.5 s, respectively, due to high Li⁺ mobility of the PADA layer. The ionic conductivities of the PADA gel electrolyte are 1.33 × 10⁻² S cm⁻¹ and 0.56 × 10⁻² S cm⁻¹ at 25 °C and −10 °C respectively, since its conductive behavior is similar to that of liquid electrolytes. The PECDs showed good cycling durability and long-term stability, which is attributed to the stable structures of the PADA gel electrolyte.