Inherent Lattice Distortion Engineering via Magnetic Field for High-Quality Strained MAPbI3 Perovskite Single Crystals

Abstract

Lattice distortion in perovskites (AMX3) significantly impacts their stability and power conversion efficiency, often in a trade-off. The inherent lattice distortion is predominantly influenced by the size, orientation, and composition of the A-site cations. Notably, organic–inorganic hybrid lead halide perovskites with organic cations like methylammonium (MA) and formamidinium (FA) demonstrate high power conversion efficiency but compromised stability. Here, a novel synthesis method is presented for high-quality strained MAPbI3 single crystals that offers not only enhanced optoelectronic properties but also improved thermal stability. This technique leverages the paramagnetic nature of the MA+ ion to manipulate lattice distortion. During the inverse temperature crystallization process, the dipole moment of the MA+ ion aligns with the direction of the external magnetic field. Correlating Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis demonstrates that this alignment, which induces compressive lattice strain, significantly enhances the carrier mobility from 68.1 to 487 cm2 V s−1, representing a sevenfold increase in hole mobility compared to the control sample. Additionally, it increases the carrier lifetime by 123%, from 23.458 to 52.364 ns, and improves thermal stability up to 230 °C. This findings reveal insights into the interplay between structural modifications and electronic properties, paving the way for tailored applications in photovoltaics, light-emitting devices, and beyond. © 2024 The Author(s). Advanced Materials Interfaces published by Wiley-VCH GmbH.