Chemical Vapor Deposition Growth Of All-inorganic Halide Perovskite Materials And Their Application In Optoelectronic Devices

In recent years,organic-inorganic hybrid perovskites,especially CH₃NH₃PbI₃,have a wide range of applications in solar cells,lasers,LEDs and photodetectors,owing to their long electron-hole diffusion lengths,tunable bandgap,high carrier mobility,low trap-state density,and high absorption coefficient.However,due to the presence of organic groups,organic-inorganic hybrid perovskites have poor light stability and thermal stability which greatly limit the application of perovskites in photovoltaic devices.Chemical vapor deposition is widely used as a method for growing high-quality semiconductor nanomaterials.However,CsPbX₃ nanomaterials have been prepared mainly by the solution method.In this paper,we discussed the growth of all-inorganic halide perovskites CsPbX₃ nanostructures by chemical vapor deposition and their applications in optoelectronic devices.We successfully grew CsPbBr₃ micro/nanorods which have unique right-angled triangular-section by chemical vapor deposition through accurate regulation of growth conditions.The experimental results suggest that as-grown triangular micro/nanorods have good crystal quality,and their growth direction is[100].The results of optical test indicate that the triangular CsPbBr₃ micro/nanorods are high quality optical cavities.In order to learn more about the optical property of CsPbBr₃ micro/nanorods,we studied their lasing behavior with femtosecond pulsed laser and confocal microscopy.The experimental results show that under the excitation of a 400 nm laser,the lasing behavior of the micro/nanorods occurs as the laser intensity increases.The Fabry-Perot-type lasing is dominant,and the lasing threshold is 14.1?J cm^-2 with high quality factor?³500?.By adjusting the ratio of halide,we successfully grew bandgap adjustable CsPbX₃ micro/nanorods with good crystal quality,and realized tunable micro-nano laser covering the range from blue light to red light.At last,in order to study the electrical property of CsPbBr₃ micro/nanorods,we fabricated the photodetector by growing CsPbBr₃ micro/nanorods directly on ITO.The responsivity is about 2.6×10⁴ A W^-1.The EQE of the device is about 8.05×10⁶%.The detectivity is about 4.78×10^-88 Jones.The rise and fall response times of the device are 51 ms and 49ms,respectively.