Study On Materials Preparation And Photoelectric Devices Of Perovskite And Zinc Oxide Composites

Halide perovskite materials have attracted wide attention for their potential applications in optoelectronics due to their high optical absorption coefficient,excellent carrier transport performance,simple fabrication process and high open-circuit voltage.In recent years,perovskite materials have made great progress in solar cell application,which have been continuously refreshed the record of power conversion efficiency?PCE?over 23%.In addition,perovskite also attract researcher's attention in optoelectronic devices such as LED and lasers due to their high optical gain,direct band gaps,high luminescence quantum efficiency,narrow PL line-widths,low preparation cost,and tunable bandwidth from blue to near-infrared.Zinc oxide?ZnO?is a classic material of II-VI semiconductor which has a large direct band gap with a band gap of 3.37 eV and a strong exciton binding energy?60meV?at room temperature.As the third generation semiconductor,ZnO has great application value in photoelectric devices,such as photodetector,solar cells,light emitting diodes,laser diodes semiconductor due to its ultraviolet luminescence,absorption and strong electronic transmission characteristics.Therefore,how to combine the advantage of two materials has important research significance and application value.The work of this dissertation is around the composite of perovskite and ZnO.perovskite quantum dots,perovskite thin films,ZnO single crystal microrods and ZnO thin films have been synthesized and prepared.On the basis of material preparation,The perovskite/ZnO composite optoelectronic devices were designed and fabricated.The research results are summarized as follows:?1?CsPbX₃?X=Cl,Br,I?quantum dots were prepared by high temperature injection method.Then the CsPbX₃ quantum dots were purified and characterized by morphology and optical characterization.The results show that the CsPbX₃ quantum dots have uniform size,narrow spectral half-width and high luminescent intensity.?2?Based on the template method and sol-gel method,the ZnO film with inverse opal structure was prepared on flexible PET/ITO substrates.Absorption spectra show that the films with microstructures had stronger optical absorption than planar structures,and could be further applied to the electron transport layer in photodetector.?3?Based on the high temperature chemical vapor deposition method?CVD?,single crystal ZnO microrod arrays were fabricated.The morphology and optical characterization showed that single crystal ZnO microrod has perfect hexagonal morphology and naturally WGM resonator.Then CsPbX₃ quantum dots were added to the single crystal microrods surface to construct a dual-band ultraviolet-visible photodetector.?4?A ZnO/CsPbBr₃ core/shell microrod was fabricated as a hybrid microcavity by a vacuum evaporation.The stimulated ultraviolet and visible emission was realized simultaneously under the 325 nm optical pumping.The lasing properties and the resonance mechanism of the dual-band laser was investigated in experiment and confirmed by two-dimensional FDTD simulation.