摘要
Organic-inorganic hybrid perovskites attract considerable attention owing to their applications in high-efficiency solar cells and light emission. Compared with three-dimensional perovskites, two-dimensional （2D） layered hybrid perovskites have a higher exciton binding energy and potentially higher light- emission efficiency. The growth of high-quality crystalline 2D perovskites with a well-defined nanoscale morphology is desirable because they can be suitable building blocks for integrated optoelectronics and （nano）photonics. Herein, we report the facile solution growth of single-crystal microplates of 2D perovskites based on a 2-phenylethylammonium （C6HsCH2CH2NHG PEA） cation, （PEA）2PbX- （X = Br, I）, with a well-defined rectangular geometry and nanoscale thickness through a dissolution-recrystallization process. The crystal structures of （PEA）2PbX4 are first confirmed using single-crystal X-ray diffraction. A solution-phase transport-growth process is developed to grow microplates with a typical size of tens of micrometers and thickness of hundreds of nanometers on another clean substrate different from the substrate coated with lead-acetate precursor film. Surface-topography analysis suggests that the formation of the 2D microplates is likely driven by the wedding-cake growth mechanism. Through halide alloying, the photoluminescence emission of （PEA）2Pb（Br, I）4 perovskites with a narrow peak bandwidth is readily tuned from violet （-410 nm） to green （-530 nm）.
Organic-inorganic hybrid perovskites attract considerable attention owing to their applications in high-efficiency solar cells and light emission. Compared with three-dimensional perovskites, two-dimensional （2D） layered hybrid perovskites have a higher exciton binding energy and potentially higher light- emission efficiency. The growth of high-quality crystalline 2D perovskites with a well-defined nanoscale morphology is desirable because they can be suitable building blocks for integrated optoelectronics and （nano）photonics. Herein, we report the facile solution growth of single-crystal microplates of 2D perovskites based on a 2-phenylethylammonium （C6HsCH2CH2NHG PEA） cation, （PEA）2PbX- （X = Br, I）, with a well-defined rectangular geometry and nanoscale thickness through a dissolution-recrystallization process. The crystal structures of （PEA）2PbX4 are first confirmed using single-crystal X-ray diffraction. A solution-phase transport-growth process is developed to grow microplates with a typical size of tens of micrometers and thickness of hundreds of nanometers on another clean substrate different from the substrate coated with lead-acetate precursor film. Surface-topography analysis suggests that the formation of the 2D microplates is likely driven by the wedding-cake growth mechanism. Through halide alloying, the photoluminescence emission of （PEA）2Pb（Br, I）4 perovskites with a narrow peak bandwidth is readily tuned from violet （-410 nm） to green （-530 nm）.
