Effects of All‐Organic Interlayer Surface Modifiers on the Efficiency and Stability of Perovskite Solar Cells

Abstract

Surface imperfections created during fabrication of halide perovskite (HP) films could induce formation of various defect sites that affect device performance and stability. In this work, all-organic surface modifiers consisting of alkylammonium cations and alkanoate anions are introduced on top of the HP layer to passivate interfacial vacancies and improve moisture tolerance. Passivation using alkylammonium alkanoate does not induce formation of low-dimensional perovskites species. Instead, the organic species only passivate the perovskite's surface and grain boundaries, which results in enhanced hydrophobic character of the HP films. In terms of photovoltaic application, passivation with alkylammonium alkanoate allows significant reduction in recombination losses and enhancement of open-circuit voltage. Alongside unchanged short-circuit current density, power conversion efficiencies of more than 18.5 % can be obtained from the treated sample. Furthermore, the unencapsulated device retains 85 % of its initial PCE upon treatment, whereas the standard 3D perovskite device loses 50 % of its original PCE when both are subjected to ambient environment over 1500 h.

Multifunctional Molecule Assists Passivate Method to Simultaneously Improve the Efficiency and Stability of Perovskite Solar Cells

“…The lifetime of τ 2 of the SN modified perovskite film is fitted to be 55.74 ns, while the control one is 38.69 ns. Obviously, two decay lifetimes of the perovskite film with SN modification are both prolonged, which indicates that the introduction of SN layer reduced defect density, restrained the nonradioactive recombination, and increased the crystalline quality of the perovskite films [45,46] …”

“…Obviously, two decay lifetimes of the perovskite film with SN modification are both prolonged, which indicates that the introduction of SN layer reduced defect density, restrained the nonradioactive recombination, and increased the crystalline quality of the perovskite films. [45,46] Usually, the interfacial dipole will arouse the additional electric field in the device, which will cause the change of the work function (W F ) of the perovskite components. To evaluate the change of the W F caused by the interfacial electric dipole formation due to the introduction of SN layer, we performed ultraviolet photoelectron spectroscopy (UPS) measurement.…”

Inorganic frameworks of low-dimensional perovskites dictate the performance and stability of mixed-dimensional perovskite solar cells

“…19,20 Meanwhile, in the second method, the pure 3D perovskite thin film is premade before it is post-treated with orthogonal solution containing LD-templating organics, allowing a thin layer of LD species to be deposited on the surface of a 3D perovskite film. 21,22 This article focuses on the mixed-dimensional HPs in which the LD HPs are incorporated in the bulk of the 3D species.…”

Molecular Locking with All‐Organic Surface Modifiers Enables Stable and Efficient Slot‐Die‐Coated Methyl‐Ammonium‐Free Perovskite Solar Modules

“…[25][26][27] Halide counterions are also prone to oxidation and diffusion. [28][29][30] As variation of crystallization kinetics and the presence of residual solvents can become more significant in large-area coating, there is, therefore, an urgent need for the development of new passivation approaches capable of addressing a wide variety of defects.…”