Magnetic-pulling Source Moving Chemical Vapor Deposition Synthesis And Optical Investigations Of CsPbCl₃/CsPbI₃ Perovskite Heterostructure Nanowires

Low-dimensional semiconductor nanomaterials play an important role in the emerging nanotechnology and optoelectronic devices.For low-dimensional semiconductor materials,many factors will affect the performance of the nanomaterials based devices,such as the absorption and luminescence efficiency of the semiconductor materials,carrier lives,and carrier mobilities et al.Owing to the limitation of natural semiconductors,high cost of traditional semiconductor synthesis,large footprint size,and the limitation of band gaps,high-integrated devices based on the nanomaterials faces great challenges.All inorganic halide perovskite have tunable bandgaps,high luminous efficiency,good stability,are good candidation for high-perforemance devices.In this article,we reported a newly developed magnetic traction source of chemical vapor deposition method to synthesize high-quality Cs Pb Cl₃/Cs Pb I₃axial perovskite heterojunction nanowires and multi-junction nanowires.Bandgap modulation has been realized by the traditional epitaxial growth technology,size effect,and alloyed semiconductor,but it is not suitable for large-scale production due to its high cost and limited application scope.Conventional chemical vapor deposition（CVD）is an important method to synthesize nanomaterials.Because of its low cost,easy operation,high yield,and large-scale production,extensive attention have been attracted.However,the traditional CVD method is hindered in the growth direction of one-dimensional semiconductor heterojunction due to the difficulties of uncontrollable Solid-state reaction sources at high temperature.Because of the shortcomings of existing technologies,a magnetic-pulling source moving CVD method are used to synthesize Cs Pb Cl₃/Cs Pb I₃ single-heterojunction nanowires and multi-heterojunction nanowires with a length of 10-30μm and a diameter of 300-700nm.The structural analysis of these single heterostructure nanowires show that these wires are axial heterostructure nanowires with single crystaline.Dark-field PL spectra and optical mapping indicate that two emission peaks at 417 nm and 698 nm are exhibited at the heterojunction,respectively,which show good agreement with the structural results.In addition,the asymmetric waveguide behavior of a single Cs Pb Cl₃/Cs Pb I₃ heterostructure nanowire under a focused laser excitation are exhibited.Moreover,a dual-wavelength nanoscale laser at 425.5 nm and 687.4 nm using this unique structure are successfully achieved.For the multi-heterostructure nanowires,large-scale guided grown nanowire arrays are fabricated on the M-plane sapphire.The ability to synthesize single or multi-heterostructure nanowires represents an important step toward high-integrated optoelectronic circuits and provides an important platform for the subsequent integration of photonic chips.