Perfluoroarenes: A Versatile Platform for Hybrid Perovskite Photovoltaics

Abstract

The instability of hybrid organic–inorganic halide perovskites presents one of the pressing challenges for their application. This is associated with the sensitivity to moisture as well as mixed ionic–electronic conductivity that leads to enhanced ion migration under conditions of voltage and light bias. Some of the most effective strategies to stabilize hybrid perovskite materials during operation involve the use of interfacial molecular assemblies and low-dimensional perovskite architectures based on hydrophobic organic moieties that could suppress the effects of moisture or ion migration. For this purpose, perfluoroarenes have provided a versatile platform due to their enhanced hydrophobicity as well as the capacity to engage in various noncovalent interactions that affect the characteristics of the resulting assemblies as well as ion migration. This Perspective discusses the emerging role of perfluoroarenes in stabilizing hybrid perovskite materials and their photovoltaic devices through different modes of action, offering insights for the design of advanced materials.

Radical reactions enabled by polyfluoroaryl fragments: photocatalysis and beyond

“…Reactions usually proceed through the functionalization of the most electrophilic fluorinated carbon (in the ortho-positions to the fluorinated atoms and in the para-position to the nonfluorine substituent). However, cases of selective functionalization of other positions are also known (see Schemes 5,27,28,35 and 36). In addition, a mechanistic test with bromo-or chloropolyfluoroarenes to determine the reaction mechanism is highly recommended for such reactions.…”

“…[1][2][3] While processes relying on specific fluorine effects associated with fluoroalkyl moieties have been extensively reviewed, the ability of fluorinated aromatic groups to serve as reactivity-enabling functionality has long been neglected, and existing reviews focus on the functionalization of the polyfluoroarene core. [4][5][6][7][8][9][10][11][12][13][14][15][16] At the same time, polyfluoroarenes are widely used for different purposes of catalysis, [17][18][19][20][21] analytical chemistry, 22,23 biochemistry, [24][25][26][27] and materials science [28][29][30][31] and their applications are well beyond the C-F bond activation. This review aims to highlight the known applications of polyfluoroarenes in organic chemistry of free radicals.…”

Recent progress in layered metal halide perovskites for solar cells, photodetectors, and field-effect transistors

“…Furthermore, an un-encapsulated (F-PEA) 2 MA 2 Pb 5 I 16 device maintained 65% of its initial PCE after 576 h at 70 °C. In the future, it may be possible to include the use of perfluoroarene-based cations 65 and their 1 : 1 mixtures with arene spacers (which went as far back as in 2003) 66 applicable to the DJ phase 67 for controlling the crystallographic characteristics and their associated properties for solar cell demonstrations.…”

Fluorinated 2-Phenylethylammonium Spacer Cations for Improved Stability of Ruddlesden–Popper Pb/Sn Halide Perovskites: Insight from First-Principles Calculations

“…It has been shown that fluorinated arylammonium cations in 2D perovskites improve the hydrophobic character of the interlayer region and further enhance the stability of the inorganic layers. − Different isomers of a chemically tuned PEA molecule have been studied to tune the properties and efficiency of the layered structures. Zhang et al have investigated the effects of functionalizing the benzene ring of PEA with F at the para position to the ethylammonium moiety.…”