I/Pb Ratio Control in the Solid Perovskite Films toward Efficient and Stable Two-Dimensional Perovskite Solar Cells

Abstract

Compositional engineering of perovskite precursors has been widely implemented to elevate the performance of perovskite solar cells (PSCs). Nevertheless, there is a lack of studies on the relationship between the I/Pb ratio and the solid perovskite film. In this work, iodine (I 2 ) was employed to tune the perovskite crystallization and control the I/Pb ratio of a two-dimensional (2D) perovskite film. A high-quality 2D (ThMA) 2 (MA) 4 Pb 5 I 16 perovskite film with wellaligned phase alignment was obtained at the optimal I/Pb ratio of 3.02. We achieved a champion device performance of 17.3% and an impressive open-circuit voltage (V oc ) of 1.19 V, which is one of the highest [power conversion efficiency (PCE)/V oc ] for thiophene spacer-based 2D Ruddlesden−Popper PSCs. Moreover, the optimized device with encapsulation demonstrated long-term operational stability, retaining 90% PCE after 500 h in dark high-humidity conditions.

High-quality perovskite films prepared by nucleus epitaxial growth for efficient and stable perovskite solar cells

“…These data clearly indicate that the n t was markedly reduced by the NEG method. 53 The dark J-V curve (Fig. S11 in ESI †) showed a lower dark current density and reduced leakage in Pero-SC with the NEG method, which transversely conrmed that defects in the perovskite lms were decreased.…”

Improved Efficiency and Stability in 1,5-Diaminonaphthalene Iodide-Passivated 2D/3D Perovskite Solar Cells

“…In comparison to the 3D perovskite film, the NDAI-passivated 2D/3D perovskite film showed superior film morphology with reduced grain boundaries and improved surface coverage, which significantly increased the absorption intensity, as shown in Figure d. The passivation of 3D perovskite films with a 2D layer increases the grain size due to several reasons, including that the organic salt used as a surfactant lowers the surface energy, facilitating the formation of larger grains during film formation, and the 2D perovskite layer formed with the cation exchange method can serve as a template for larger grain growth. , Atomic force microscopy (AFM) also confirmed the comparatively smooth morphology in 2D/3D perovskite films having an rms surface roughness of 6.21 nm in comparison to the 11.23 nm roughness of the pristine 3D perovskite film (Figure S5).…”

Comparative Analysis of Thiophene-Based Interlayer Cations for Enhanced Performance in 2D Ruddlesden–Popper Perovskite Solar Cells

“…Remarkably, even after 500 h under dark, high humidity conditions, the PCE of these devices remained stable at 90%. 36 In 2022, by using (TMA) transparent material with strong green luminescence. 37 While both TMA and TEA have found widespread applications in 2D PSCs, it is worth noting that there is limited research exploring the differences between these two compounds and the influence on the performance of 2D PSCs.…”

“…In 2022, Li et al successfully synthesized high-quality 2D (TMA) 2 ­(MA) 3 ­Pb 4 I 13 perovskite thin films, ultimately achieving a champion device efficiency of 17.3%. Remarkably, even after 500 h under dark, high humidity conditions, the PCE of these devices remained stable at 90% . In 2022, by using (TMA) 2 PbI 4 and (TEA) 2 PbI 4 as precursors, Zanetta et al prepared (TMA) 2 PbICl 3 and (TEA) 2 PbICl 3 , resulting in a transparent material with strong green luminescence .…”