Spacer Engineering of Thiophene-Based Two-Dimensional/Three-Dimensional Hybrid Perovskites for Stable and Efficient Solar Cells

Abstract

Organic spacers play a crucial role in two-/three-dimensional (2D/3D) hybrid perovskite-based solar cells that integrate the advantages of the stability of 2D perovskites and the high efficiency of 3D perovskites. However, improving the stability of the device without compromising the high photovoltaic efficiency in 2D/3D perovskite solar cells using large organic cations in 2D perovskite is a challenge. Herein, we synthesized 2-thiopheneethylammonium iodide (TEAI) and found that TEAI can perform as a spacer for 2D/3D hybrid perovskites. TEAI with a bulky aromatic spacer in 2D/3D hybrid perovskites can effectively induce crystalline growth and orientation, leading to a longer carrier lifetime, higher carrier mobility, fewer surface, and grain boundary defects. The inclusion of TEAI also improves surface hydrophobicity. The 2D/3D hybrid perovskite device based on TEAI achieved the highest efficiency of 18.75% compared with the 16.83% efficiency of the 3D perovskite device. After aging for 1000 h in an ambient atmosphere, the unpackaged 2D/3D hybrid perovskite solar cells maintained approximately 82% of their initial efficiency, whereas that of the controlled devices decreased to approximately 47% of their original performance. These results suggest that TEAI can be used as an organic spacer for the preparation of high-efficiency and high-stability 2D/3D perovskite solar cells.

Efficient and Stable 3D/2D Perovskite Solar Cells through Vertical Heterostructures with (BA)4AgBiBr8 Nanosheets

“…[35,[43][44][45] Therefore, we further measured the thermostability and photostability of PVSC based on 3D/2D heterostructure and control device. [18,21,22] As shown in Figure 4a,b, the evolution of PCE, V OC , FF, and J SC over 1000 h was recorded for the control and 3D/2D devices under 65 °C in nitrogen atmosphere. The PCE of the control device decayed rapidly to less than 75% of its original value after 1000 h. In contrast, the 3D/2D device retained over 89% of its original efficiency.…”

“…[8][9][10][11][12] Charge-transporting materials modification, surface defects passivation, and dimensional engineering are the most adopted strategies to suppress the nonideal interfacial recombination and reduce the energy losses in PVSCs. [13][14][15][16][17][18][19] Among them, the defects at the grain boundaries of 3D perovskite can act as recombination and trapstate centers for minority carriers, which are always considered detrimental to performance. [20] Therefore, the 3D/2D heterojunction architecture stands out as it can simultaneously passivate defects at grain boundaries, modify the interfacial energy alignment, and suppress the ion diffusion, thereby enhancing the device performance and long-term stability.…”

Surface Passivation by Sulfur-Based 2D (TEA)2PbI4 for Stable and Efficient Perovskite Solar Cells

“…With the incorporation of TEAI, a small amplitude peak at q z ≈ 0.4 Å –1 emerged which is attributed to the formation of 2D perovskite on the 3D layer. Moreover, several distinct peaks appear in 3D/2D layers along out-of-plane at a lower angle ( q < 0.75 Å –1 ) that also reported to the 2D layered material . After treatment with TEAI, the intensity of the (110) plane of the perovskite along out-of-plane is significantly increased (Figure S6d), indicating improved crystallinity of the films, which can contribute to enhancement of the PCE and stability of PSCs …”

Influence of Two- and Three-Dimensional Engineering on the Trap State Distribution and Photophysical Properties of Lead Halide Perovskite Polycrystals

“…Methylammonium lead iodide (CH 3 NH 3 PbI 3 ) perovskite polycrystalline films post-treated with different concentrations of PEAI were fabricated via the well-established spin-coating method (see Figure S1 for experimental details). 28 By treating the as-prepared perovskite films with 10 mg/mL of PEAI, as illustrated by the scanning electron microscopy (SEM) images (Figure 1a), a flake-shaped layer on the top of the 200 nmsized 3D perovskite polycrystals is recognized. The corresponding X-ray diffraction (XRD) spectra (Figure 1b) manifest that 2D perovskite nanosheets, as characteristic of the diffraction peak at 6.6°, 29 are formed when the PEAI concentration exceeds 3 mg/mL.…”