Enhanced Perovskite Solar Cell Stability and Efficiency via Multi‐Functional Quaternary Ammonium Bromide Passivation

Abstract

using low-cost precursor materials and solution-based methods, made it more acceptable for industrial applications. [6][7][8] However, the inevitable defects on the surface and grain boundaries during the fabrication still blocks the further development. [9,10] These defects would damage the quality of the perovskite films and provide sideways for ions migration, [11] leading to the seriously effect on the transport of carriers. Specially, when exposed to the environment, the perovskite films would be attacked by the moisture and oxygen, resulting to the irreversible degradation of perovskite films and finally the devices. [12,13] Strategies, like defect passivation, have been proved effective to treat to render the surface less reactive chemically. [14][15][16][17][18] The ionic bond between anion and cation has caused extensive research, as the introduction of metal cations Cs + , [19,20] K + , [21] and Rb +[22] usually has a positive effect on the I interstitial and the anti-site substitution of Pb−I, while the anions Br −[23] and Cl −[24] are usually used to passivate lead interstitial and halide vacancies. Lewis acids and bases have been proven functional in bonding with uncoordinated halides or metal ions in the perovskite crystals to form Lewis adducts, thereby reducing the density of defects. [25][26][27] Ma et al. introduced nicotinamide as a Lewis base additive into the perovskite precursor solution, which found that the nicotinamide in the perovskite film can passivate the surface and grain boundary defects, control the morphology of the film, and improve the crystallinity. [25] Wang et al. evidenced that BA + can form a two-dimensional (2D) layered perovskite with a wide band gap upon the threedimensional (3D) perovskite. [28] When migrating to the grain boundaries in the 3D perovskite layer, the carriers are blocked by the 2D/3D heterojunction and continue to propagate in the crystal grains rather than by recombination. The method of low-dimensional perovskite passivation 3D perovskite has positive effect of improving the efficiency and stability of PSCs. [25][26][27][28][29][30][31] Even though the quality of the perovskite films were optimized by the reported effective passivation methods, but most of the optimization are conducted by single functional, and the optimized perovskite still suffers from the corrosion of the external environment (such as high humidity) directly. Therefore, it's time to develop suitable passivators with functional groups which not only for passivated defects, but also need external protective functional groups for resistance to environmentalThe Achilles heel of the perovskite solar cells (PSCs) is the long-term stability under working condition which restricts the commercialization. There are many causes for the poor stability including intrinsic defects in perovskite and humidity-induced degradation. This work systematically investigates the synergistic working mechanism of defect passivation and humidity erosion protection on organic-inorganic metal-halide perovski...

Low-cost and LiTFSI-free diphenylamine-substituted hole transporting materials for highly efficient perovskite solar cells and modules

“…The doped SC-2 devices exhibit a slightly higher J SC and FF, and a significantly higher V OC as compared to the devices based on doped EH44. Since the additional benzene ring in SC-2 increases the conjugation effect and thus the conductivity of the film, 37 this superior performance can be explained by the chemical nature of SC-2. In addition, the isooctyloxy group in SC-2 can act as the Lewis site, which is reported to be able to interact with adjacent perovskites and improve the contact between the active layer and HTL.…”

Taurine as a powerful passivator of perovskite layer for efficient and stable perovskite solar cells

“…A smaller series resistance (R S ) of 9.37 U was displayed by the MAPbI 3 :Taurine device than the MAPbI 3 device (46.20 U), which indicates faster carrier transportation in the MAPbI 3 :Taurine device. 37,38 On the other hand, the charge recombination resistance (R rec ) was signicantly raised from 8.38 kU to 16.87 kU by the accession of Taurine, which was benecial to inhibit the carrier recombination, leading to an increased V OC . 37,38 Furthermore, the capacitance of the constant phase element (CPE) at the low-frequency region of the MAPbI 3 :Taurine device was much lower than the control device, which indicates suppressed ion accumulation in the MAPbI 3 :Taurine device due to the effective passivation of defects.…”

“…37,38 On the other hand, the charge recombination resistance (R rec ) was signicantly raised from 8.38 kU to 16.87 kU by the accession of Taurine, which was benecial to inhibit the carrier recombination, leading to an increased V OC . 37,38 Furthermore, the capacitance of the constant phase element (CPE) at the low-frequency region of the MAPbI 3 :Taurine device was much lower than the control device, which indicates suppressed ion accumulation in the MAPbI 3 :Taurine device due to the effective passivation of defects. The detailed R S , R rec , and the capacitance of CPE value are listed in Table S3.…”

Fabrication of a Water-Stripped Free-Standing Silver Nanowire Network as the Top Electrode for Perovskite Solar Cells

“…These cells have achieved a remarkable power conversion efficiency (PCE) of 26.1%, which is comparable to that of single-crystal Si solar cells and surpasses both multicrystalline Si solar cells and Cu­(In,Ga)­Se 2 -based (CIGS) solar cells . Despite these achievements, the development of PSCs with high PCE, low fabrication cost, environmentally friendly materials, long-term stability, and large light-absorbing area, as well as their integration into flexible and sustainable devices, still presents a challenge and has recently emerged as a popular research area. − One critical aspect for commercial applications is the fabrication process. Most studies reported in the literature employ thermal evaporation to prepare the top metallic electrodes of PSCs, which require a vacuum atmosphere.…”