Layered Arrangement of 1D Wavy Chains in the Lead‐Free Hybrid Perovskite (PyrCO₂H)₂BiI₅: Structural Investigations and Properties

Abstract

Lead free organic-inorganic hybrid perovskites have attracted increasing attention because of their variety of applications such as photovoltaics or lighting. Here, we reported a new iodobismuthate organic-inorganic perovskite (PyrCO 2 H) 2 BiI 5 where PyrCO 2 H + is the 4-carboxy-1-methylpyridinium. In the room temperature orthorhombic phase, the one-dimensional (1D) inorganic framework which consists of cis-connected corner-sharing BiI 6 octahedra, exhibits a sinusoidal deformation along the chain axis, while a regular chain leading to a sub-cell is found in the high temperature phase (T > 390 K). An original structural feature is the relative position of consecutive 1D chains in planes leading to a layered character of this organicinorganic compound. The electrical properties as function frequencies and temperatures have been studied in particular allowing the extraction of R g and further the calculation of σ g = f(T). Interestingly, a change of activation energy is detected at the phase transition temperature (390 K). The higher value of activation energy above 390 K can be attributed to change of the conduction mechanism involving ionic conduction.

Polymorphism and Red Photoluminescence Emission from 5s2 Electron Pairs of Sb(III) in a New One-Dimensional Organic–Inorganic Hybrid Based on Methylhydrazine: MHy2SbI5

“…It may seem that this is another example of a structure in which the presence of MHy enforces an acentric arrangement of atoms. However, upon comparing the data on structures with the A 2 SbI 5 stoichiometry it can be observed that the majority of them crystallize in non-centrosymmetric or polar space groups [ 26 , 51 , 52 ]. Hence, the absence of a center of symmetry in polymorph I should be attributed to the unique properties of this specific stoichiometry.…”

“…Hybrids with the general formula R 2 SbI 5 have already garnered significant attention from scientists as potential functional materials. This is owing to their outstanding properties, which include a strong second harmonic generation (SHG) response [ 32 , 47 , 48 ], ferroelectricity [ 48 , 49 ], a small bandgap with strong absorption ability [ 31 , 33 , 34 , 48 , 49 , 50 , 51 , 52 ], switchable dielectric properties [ 53 ] and excellent thermal stability [ 31 ]. Herein, we show the crystal structure and temperature behavior of two new polymorphic forms, temperature dependent structural phase transitions, thermal characteristics as well as luminescent properties.…”

Halogen‐Modulated Reversible Phase Transition in Organic‐Inorganic Hybrid Perovskites

“…They are assembled by intermolecular interactions between organic cations and inorganic framework anions [6–20] . This combination integrates organic and inorganic parts′ advantages, bringing extraordinary optoelectronic properties, such as dielectric, piezoelectric, ferroelectric, and fluorescent properties [21–37] …”

“…[6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] This combination integrates organic and inorganic parts' advantages, bringing extraordinary optoelectronic properties, such as dielectric, piezoelectric, ferroelectric, and fluorescent properties. [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] The lead-based phase transition materials have been studied more extensively. For example, it was reported in 2019 that Xiong et al prepared the first organic-inorganic hybrid perovskite (4,4-DFPD) 2 PbI 4 (4,4-DFPD = 4,4-difluoropiperidinium) and revealed interesting ferroelectric vortex structures.…”