Screw-Dislocation-Driven Growth of 2D Perovskite Spiral Microplates.

Abstract

Two-dimensional (2D) organic-inorganic halide perovskites are solution-processable semiconductors that are promising for optoelectronic applications. Understanding crystallization mechanisms to achieve control over nanostructures is important for optimizing desired properties. Here we introduce a versatile strategy to synthesize spiral microplates of diverse 2D perovskites at the air-water interface through screw-dislocation-driven growth. Spirals of 11 2D perovskite compositions (LA)₂(A)_n-1Pb_nX_3n+1 with different spacer (LA) cations, A-cations, halide (X) anions, and n-number can be grown. They typically consist of single- or few-layer perovskite step heights but exhibit stacking complexity when multiple dislocations interact. The spiral microplates exhibit the characteristic optical properties (photoluminescence and second-harmonic generation) of the underlying 2D perovskites. Fluorescence-detected circular dichroism imaging shows that the chirality of the spiral center does not translate to the observed chiroptical properties of the microplate, consistent with the length scale of the chiral distortion. This solution growth of perovskite spirals diversifies the perovskite microstructures for optoelectronics and other applications.