Phonon mode transformation in size-evolved solution-processed inorganic lead halide perovskite

Recently, lead halide perovskites have attracted significant scientific attention in the fields of photovoltaics, light emitting diodes, lasers, photo-detectors and other optoelectronic functional devices. The most stable crystal form of lead halide perovskites is the cube, including nano-cube and micro-cube, which hold great promise as functional materials due to their combination of unique optoelectronic properties and versatility through colloidal synthesis. Herein, we report the solution-processed synthesis of pure inorganic lead halide nano-cubes- and micro-cubes-based colloidal perovskites. The different size of cubes either into nano-cube or micro-cube are demonstrated that their phonon mode transformation which means the perovskite crystal structure phase change cross the nano-cube to micro-cube. The solution-processed colloidal synthesis method and phonon-mode transformation from nano-cube to micro-cube make pure inorganic lead halide perovskite an ideal platform for fundamental optoelectronic studies and the investigation of functional devices.