Electric-field-induced phase transition in 2D layered perovskite (BA)(2)PbI4 microplate crystals

Two-dimensional (2D) lead halide perovskite materials are solution-processable semiconductor materials, which would find promising applications in optoelectronic devices. The fundamental understanding of the structural phase transition in two-dimensional perovskites is of great importance for fully exploiting their potential applications in electronic and optoelectronic devices. Here, we report on how the external electric field affects the structural phase transition in 2D perovskite (BA)(2)PbI4 microplates via temperature-dependent photoluminescence spectroscopy. A high-temperature phase and a low-temperature phase can coexist in a wider range of temperatures. The external electric field would enhance the phase transition to the dominant phase depending on the surrounding temperature. This field-induced phase transition might be ascribed to the release of strain in the perovskite microplate induced by the applied electric field, leading to the change in the structural phase transition temperature. Our findings are of great significance not only to the fundamental understanding of phase transition but also to the design and optimization of two-dimensional perovskite based electronic and optoelectronic devices.