Iodine Induced PbI₂ Porous Morphology Manipulation for High‐Performance Planar Perovskite Solar Cells

Abstract

The quality of the perovskite film has a vital influence on the performance of perovskite solar cells and it is quite desirable to simultaneously manipulate the crystallization and morphology of the perovskite film. In this study, conventional PbI2 is replaced with a PbI2/I2 mixed precursor during the first step of sequential deposition, causing the formation of a PbI2 porous nanostructure. By changing the content of I2 in the precursor, the morphology of the PbI2 film as well as the resulting perovskite film can be successfully modulated. With an optimal content of I2, a high‐quality perovskite film with a pure phase and smooth surface can be achieved. As a result, the conversion efficiency of perovskite solar cells using a PbI2/I2 mixed precursor can be as high as 18.63%, compared to 16.89% for the reference device through traditional sequential deposition with a pure PbI2 precursor.

Fluorinated Alcohol-Processed N-Type Organic Electrochemical Transistor with High Performance and Enhanced Stability

“…The average depth of nanopores was estimated to be ∼120 nm for gNR-9FOH , as revealed by the cross-sectional analyses of the AFM height images (Figure S12b). The pores within the three-dimensional network provide a large specific surface area and can potentially facilitate the contact and doping for water molecules and further sodium ions, which reflect in the largest volumetric capacitance of gNR-9FOH . , Nevertheless, electron mobility is intensively affected by the film surface morphology, and the absorption of a large amount of water molecules in the film will also lead to disconnected regions for intercrystallite electronic charge transport to a certain extent, which will inhibit the smooth electronic transport. , To further illustrate the reason why FA solvent-fabricated OECTs display a better operational stability than that of CF, we also compared the morphology evolution of the films before and after multiple doping/dedoping cycles by applying a square-wave voltage switching between 0.5 and 0 V vs Ag/AgCl. From the absolute height distribution of pristine and doped films (Figure S12), a sharp decrease of the RMS roughness from 13.5 to 4.7 nm was observed for the gNR-CF film, suggesting the seriously damaged morphology upon 600-cycle doping/dedoping.…”

Consolidating a Pb–X framework via multifunctional passivation with fluorinated zwitterions for efficient and stable perovskite solar cells

“…S5,† resulting in increased light scattering. 47 The porous and rough PbI 2 film morphology not only improves the surface morphology of the perovskite film, but it also facilitates the more complete conversion of PbI 2 to perovskite. This result agrees with the SEM and XRD characterization results for the perovskite films.…”

High Moisture Stability for Enhanced Quality Perovskite Solar Cells Induced by Front and Back Layer Synergistic Passivation of Perovskite

“…I 2 volatilized during the annealing process without leaving impurities, and successfully controlled the shape of PbI 2 film. [ 14 ] Therefore, it is feasible to improve the performance of perovskite devices by altering PbI 2 morphology in two‐step method.…”