Realizing High‐Efficiency Perovskite Solar Cells by Passivating Triple‐Cation Perovskite Films

Abstract

The photovoltaic performance of perovskite solar cells (PSCs) prepared by the low‐temperature solution method has made rapid progress. However, the surface of the film is prone to defects that trap photogenerated charges, resulting in nonradiative recombination energy loss and limiting the open‐circuit voltage and overall performance of the device. Interface passivation as an effective method can significantly reduce defects and inhibit nonradiative recombination. Herein, a simple method is introduced to passivate perovskite films by a carboxylated (–COOH) sensitizer that is applied in dye‐sensitized solar cells (DSCs), 4‐(bis(9,9‐dimethyl‐9H‐flouren‐2‐yl)amino)‐1‐naphthoic acid (KTN) molecules. The research results show that the chemical interaction between KTN and iodide vacancies exposing Pb2+ can reduce the nonradiative recombination and elongate the carrier lifetime, which leads to an excellent power conversion efficiency (PCE) with 23% with an obvious increase in open‐circuit voltage (VOC) of 60 mV. Moreover, the defect passivation can significantly enhance the stability of corresponding PSC devices. The unencapsulated device with KTN passivation can readily maintain ≈90% of its initial efficiency value after 1400 h. These findings may provide a novel approach for interfacial defect passivation to further promote the performance and stability of PSCs.

Bifunctional hole-shuttle molecule for improved interfacial energy level alignment and defect passivation in perovskite solar cells

“…Such a hole transfer is energetically favoured as discussed above since the CBz-PAI HOMO level is 40 meV higher than the perovskite valence band edge. level alignment with the perovskite layer to improve charge transfer 20,[33][34][35] ; however, device performances of these works are far from state-of-the-art. Recently, two-dimensional (2D) layered perovskites based on bulky cations applied to the surface of three-dimensional (3D) perovskite thin films to generate 2D/3D heterojunction with better band alignment have attracted considerable attention, and a significant improvement in device performance has been shown 22,36 .…”

Construction of Efficient and Stable FAPbI3 Perovskite Solar Cells through Bifunctional Ionic Liquid‐Assisted Crystallization and Defect Passivation

“…Organic-inorganic halide perovskite solar cells (PSCs) have attracted great research interest due to their superb optoelectronic properties. [1][2][3][4][5][6][7] In the past decade, the record power conversion efficiency (PCE) of all-solid-state single-junction thin-film PSCs has jumped from 9.7% to 25.7%, mainly benefiting from the enormous compositional and interface engineering. [8][9][10][11][12][13][14] For PSCs achieving record PCE and stability, the perovskite layer was turned from the original MAPbI 3 -to FAPbI 3 -based compositions.…”

Molecularly Tailored Surface Defect Modifier for Efficient and Stable Perovskite Solar Cells

“…The peak of excess PbI 2 (2𝜃 = 12.7 °) is observed in the pristine perovskite film, which is consistent with the previous report. [37,38] While the signal of PbI 2 phases disappears after the TMBAI treatment, suggesting that TMBAI can react with excess PbI 2 at the perovskite surface (Figure 1f; Figure S6, Supporting Information). [39] The XRD results of PbI 2 , TMBAI and TMBAI/PbI 2 films are also compared, as shown in Figure S7 (Supporting Information).…”