Cyclopropenium (C₃H₃)⁺ as an Aromatic Alternative A-Site Cation for Hybrid Halide Perovskite Architectures

Abstract

Hybrid halide perovskites are an emerging class of photovoltaic materials, boasting high solar efficiencies from relatively simple preparations. However, the chemical diversity of the A-site organic cation is limited, generally due to steric constraints of the (PbI 3 ) Ñ cage. Herein we describe the use of a non-benzenoid HŸckel aromatic, (C 3 H 3 ) + , as a viable alternative to the readily employed methylammonium, formamidinium and guanidinium A-site cations. (C 3 H 3 ) + may lead to greater moisture stability due to the lack of an acidic proton relative to the current (H-NR 3 ) + Ðbased systems while still boasting a narrow electronic band gap (E g = 1.5 eV) and highly mobile holes and electrons (! ! ! = -1.27 and ! ! ! = 0.77, respectively). TOC GRAPHICS

Role of Polycyclic Aromatic Alkylammonium Cations in Tuning the Electronic Properties and Band Alignment of Two-Dimensional Hybrid Perovskite Semiconductors

“…Two-dimensional (2D) hybrid organic–inorganic perovskites (HOIPs) have recently attracted considerable research interest. − The unique photophysical properties induced by spatial and dielectric confinement effects make 2D HOIPs attractive for many optoelectronic applications, such as photovoltaics, light-emitting diodes (LEDs), and photodetectors. − Compared to their three-dimensional analogues, 2D HOIPs show improved stability and wider structural and chemical flexibility, , which enables the tuning of optoelectronic properties by modifying the layer thicknesses and the composition of organic and/or inorganic components. ,− …”

Isomer-specific photofragmentation of C3H3+ at the carbon K-edge

“…14,15 A possible application for c-C 3 H 3 + could be the integration into hybrid halide perovskite architectures, which may be used as a photovoltaic material. 16 C 3 H 3 + is difficult to study in isolation due to its charge. Solutions to the problem are to investigate the ion in an ion trap or a free ion beam moving in a vacuum with a kinetic energy of several keV and selecting it by mass-spectrometric techniques.…”

Recent progress in construction methods and applications of perovskite photodetector arrays

“…1b). 3,4 This unique crystal structure gives the metal halide perovskites excellent optoelectronic properties such as high absorption coefficient, 5,6 tunable optical bandgap, 7 low defect density, 8 and long charge carrier diffusion length and lifetime. 9,10 The bandgap of the ABX 3 perovskite with different components is shown in Fig.…”