Research On Synthesis Of One-dimensional Halide Perovskite And Its Ultraviolet Polarization Detection

In recent years,as one of the"new stars"in the field of semiconductor materials,one-dimensional lead halide perovskite nanowires（NWs）have become a new potential semiconductor material in the field of optoelectronic devices,which due to their special morphology with high aspect ratio,dielectric confinement effect and polarization anisotropy.One-dimensional perovskite NWs have the advantages of good fluorescence quantum efficiency and adjustable band gap,the high aspect ratio of their morphology gives them strong polarization characteristics,making them stand out from other semiconductor nanocrystals in a variety of applications.However,in order to achieve strong polarization luminescence characteristics,NWs needs to be oriented,in order to show certain anisotropic optical characteristics.In this paper,we first proposed a synthesis strategy assisted by HBr ligand to prepare Cs Pb Br₃ NWs;Secondly,NWs oriented polymer optical conversion films are realized based on mechanical stretching method.At this time,the polarization of highly oriented films will be significantly improved.Finally,the spectral conversion film with polarization selective characteristics is used to study the enhancement of UV polarization detection.The specific research contents are as follows:（1）First,we prepared Cs Pb Br₃ NW_S solution with appropriate length by ultrasonic assisted synthesis and oleic acid-oleylamine ligand system with hydrobromic acid（HBr）.Compared with the reported products,NWs has better one-dimensional morphology,higher aspect ratio and high PLQY.Compared with thermal injection method,ultrasonic assisted synthesis method does not need strict protection of inert gas environment,has short reaction time and simple experimental conditions,can significantly reduce manufacturing time and production cost,and can provide some practical ideas for commercial mass production mode.（2）Secondly,we mixed the NWs products and polymethyl methacrylate（PMMA）uniformly to make the polymer composite thin film with strong fluorescence efficiency.The NWs in the film would be aligned along the tensile direction by mechanical stretching.At this time,the degree of polarization of highly oriented films would be significantly improved.（3）Finally,the spectral conversion film with polarization selection characteristics is used to convert the light in the blind ultraviolet band into visible light in the 520nm band,and the polarization imaging of specific patterns is realized by the CCD camera.This kind of strong polarization light-emitting film is applied to the imaging device of UV spectrum efficient conversion film.It is found that the spectral conversion enhancement film can not only retain the detected UV polarization information,but also realize the spectral conversion of 266nm to520nm light-emitting wavelength,which makes up for the shortage that it is difficult for CCD equipment to receive UV signal for high-quality UV polarization imaging.