Preparation And Study Of The Mechanoluminescence Properties Of CsPbX₃/ZnS Composite Materials

Mechanoluminescence（ML）materials are materials that produce luminescence by mechanical stimulation,that show great potential in light sources,displays,biological imaging and pressure sensors.However,the application of ML materials is severely limited by the lack of color of the spectral emission band and the weak red light.On the other hand,all-inorganic perovskite quantum dots（CsPbX₃,X=Cl,Br,I）have the excellent characteristics of large absorption range and high photoluminescence quantum yield,and the luminescence color is adjustable in the whole visible spectral range.Therefore,the flexible composite films was prepared by combining all-inorganic perovskite quantum dot material with zinc sulfide phosphor to control its stress luminescence properties under mechanical force.The main study content of this paper includes the following two aspects:Firstly,Pe QDs were synthesized by hot injection method and embedded in ethylene-vinyl acetate copolymer（EVA）material.Through X-ray diffraction pattern,ultraviolet-visible absorptionspectrum,emission spectrum,life and other material structure and optical performance tests,it is founded that the perovskite quantum dots embedded in EVA have good flexibility and luminescence stability,and the luminescence peak position does not change any more,which is suitable for further application of optical devices.Then,the flexible composite film of CsPb（Br/I）₃/EVA/ZnS/PDMS was prepared by spin-coating method.By changing the data of concentration of perovskite quantum dots,halogen elements,the intensity and frequency of applied tensile stress,the mechanical luminescence spectra of the composite films were controlled.The experimental results show that CsPb（Br/I）₃/EVA/ZnS/PDMS has excellent mechanical luminescence characteristics.The mechanical luminescence spectrum is finely adjustable in the range of 510-710 nm,and the full width at half maximum in the range of 11-38 nm.The mechanical luminescence intensity increases linearly with the frequency of tensile stress,and it also have good performance in the luminescence repetitive.It can achieve 500cycles of mechanical luminescence without changing the intensity of luminescence.At the same time,under the action of tensile stress,the composite film can realize multi-color graphic display and white luminescence.The above results show that the composite film prepared in that experiment has the potential of application in the fields of force-light sensor,piezoelectric photon display,new white light source and so on.