Supramolecular Interactions of Flexible 2D Perovskite in Microstrain Releasing and Optoelectronic Properties Recovery

Abstract

The conductivity of 2D perovskite is mainly dominated by halide metal octahedron skeletons. However, in contrast to 3D perovskite structures, the layered inorganic skeletons are easily compressed or stretched by large organic cations, causing serious microstrain with impaired optoelectronic responses. Here, fluorination modulated supramolecular interactions in 2D fluorophenethylammonium lead iodide (FPEA 2 PbI 4 ) perovskites are reported. In the double layered organic spacer, interlayer supramolecular interactions between electronegative F atoms and electron-rich benzene rings dominate the lattice microstrain of 2D (p-FPEA) 2 PbI 4 perovskite, which can be released by interlayer interactions pulling during compressively bending the flexible devices. This strong electrostatic interaction can maximally release the compression to the inorganic octahedron skeleton during compressive bending, leading to a maximum degree of released microstrain with improved stability. The 60% microstrain can be released by compressive bending, and the corresponding photocurrent response is recovered by about three times in (p-FPEA) 2 PbI 4 perovskite film. In contrast, intralayer supramolecular interactions dominate microstrain of 2D (o-FPEA) 2 PbI 4 perovskites, which prevents the microstrain release during compressive bending. The strong electrostatic interaction design in the organic spacer of 2D perovskite takes an important role in releasing the microstrain and re-bursting the device performance of flexible perovskite devices.

Centimeter‐Sized Single Crystals of Dion‐Jacobson Phase Lead‐Free Double Perovskite for Efficient X‐ray Detection

“…[32,33] To some extent, the penetration depth of organic cations affects the distortion degree of the inorganic monolayer. [28,34] The penetration of NH 3 in 1 has a large value (≈1.0 Å) (Figure S2, Supporting Information), which results in a large average bond angle of 169.85 ° (180 ° and 159.7 ° along b and a-axis, respectively.) for Sb-Br-Ag (Figure S3, Tables S2 and S3, Supporting Information).…”

Low Bandgap 2D Perovskite Single Crystal with Anomalous‐large Charges/ions Collection Ratio for Ultra‐sensitive and Stable X‐ray Detectors

“…To compare the activation energy of mobile ions with other MHPs, the temperature‐dependent conductivities of these two single crystals were measured in Figure 3e. These two single crystals both possess clear conductive characteristics below 385 K. The ion activation energy ( E a ) of these two single crystals along the out‐of‐plane direction were further derived by the following Nernst–Einstein Equation 3: [36] $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr \sigma \left(T\right)={{{\sigma }_{0}}\over{T}}{\rm exp}\left({{{-E}_{{\rm a}}}\over{{k}_{{\rm B}}T}}\right)\hfill\cr}}$$$ …”

Low Bandgap 2D Perovskite Single Crystal with Anomalous‐large Charges/ions Collection Ratio for Ultra‐sensitive and Stable X‐ray Detectors

“…To compare the activation energy of mobile ions with other MHPs, the temperature‐dependent conductivities of these two single crystals were measured in Figure 3e. These two single crystals both possess clear conductive characteristics below 385 K. The ion activation energy ( E a ) of these two single crystals along the out‐of‐plane direction were further derived by the following Nernst–Einstein Equation 3: [36] $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr \sigma \left(T\right)={{{\sigma }_{0}}\over{T}}{\rm exp}\left({{{-E}_{{\rm a}}}\over{{k}_{{\rm B}}T}}\right)\hfill\cr}}$$$ …”