Efficient Inorganic Vapor‐Assisted Defects Passivation for Perovskite Solar Module

Abstract

the spin-coating assisted passivation by organic molecules is easy failure due to the secondary bond such as ionic bond and hydrogen bond, [10] meanwhile, the low concentration of organic molecule passivated perovskite film is inhomogeneity, resulting in the inadequacy defects passivation. [11] Significantly, the solvents (such as isopropanol and chloroform) of passivated organic molecules also reconstruct the perovskite surface causing the uncertain type and number of defects and the weak property reproduction of PSCs. [12] While vapor-assisted defects passivation can efficiently avoid the disadvantages, thus is suitable for large-area perovskite film production instead of the solvent passivation method through the spin-coating process, which is rarely studied.Herein, we propose the inorganic vapor-assisted passivation strategy to deposit CS 2 inorganic passivation layer for high-efficiency and large-area perovskite solar module (PSM). The CS 2 molecule efficiently manages surface defects, regulates interfacial energy alignment, and enhances the properties of PSC. The uncoordinated Pb 2+ and unanchored I − on the surface of perovskite film have been passivated by the CS 2 through in situ reaction. The CS 2 can stabilize the perovskite by forming strong chemical bonds with the soft perovskite thin film, signi ficantly impeding the decomposition of perovskite components and reducing trap-state density at the grain boundaries and interfaces. Consequently, inorganic vapor-assisted defects passivation simultaneously enhances the PSC devices' efficiency and Surface trap as intrinsic defects-mediated non-radiative charge recombination is a major obstacle to achieving the reliable fabrication of high-efficiency and large-area perovskite photovoltaics. Here a CS 2 vapor-assisted passivation strategy is proposed for perovskite solar module, aiming to passivate the iodine vacancy and uncoordinated Pb 2+ caused by ion migration. Significantly, this method can avoid the disadvantages of inhomogeneity film caused by spin-coating-assisted passivation and reconstruction of perovskite surface from solvent. The CS 2 vapor passivated perovskite device presents a higher defect formation energy (0.54 eV) of iodine vacancy than the pristine (0.37 eV), while uncoordinated Pb 2+ is bonded with CS 2 . The shallow level defect passivation of iodine vacancy and uncoordinated Pb 2+ has obviously enhanced the device efficiencies (25.20% for 0.08 cm 2 and 20.66% for 40.6 cm 2 ) and the stability, exhibiting an average T 80 -lifetime of 1040 h working at the maximum power point, and maintaining over 90% of initial efficiency after 2000 h at RH = 30% and 30 °C.

In situ formation of an inorganic lead oxysalt surface passivation layer for highly efficient and stable CsPbI3 perovskite solar cells

“…The improvement of film crystallization by surface passivation has also been proven in a previous report. 41 To further study the effect of AC treatment on the crystallinity of the perovskite film, grazing incidence XRD (GIXRD) was performed to characterize the crystal structure of the perovskite film surface. Fig.…”

Synergistic Modification for Efficient Perovskite Solar Cells with Small Voltage Loss

“…The peaks of I 3d also shift to a slightly higher binding energy (Figure c). The shifting of Pb 4f 5/2 and Pb 4f 7/2 peaks may be due to the interaction between the –COO – group and undercoordinated Pb 2+ . − The strong peaks at 533.79 and 532.24 eV belong to the C–O and CO bonds in Ac – , respectively, suggesting that Ac – remains in the final perovskite films. The perovskite film made without using Pb­(Ac) 2 shows a weak peak at 532.30 eV (CO bond), which is caused by the adsorbed carbon dioxide (CO 2 ) on the surface. − …”

Recent major advancements in perovskite solar cells

“…Unfortunately, despite many efforts, a decline in efficiency is unavoidable when the module area increases [50,121,[137][138][139]. This trend is evident from the graph of maximum efficiency records for devices of various areas shown in figure 11.…”