Preparation method and application of red fluorescent powder comprising lead methylamine iodide and methylamine iodine

The invention discloses a preparation method and application of red fluorescent powder comprising lead methylamine iodide and methylamine iodine. The red fluorescent powder adopts a chemical formula of CH3NH3PbI3: xCH3NH3I, wherein x is 0-10. The preparation method comprises the following steps: with methyl ammonium iodide, lead iodide and DMF as raw materials, weighing the methyl ammonium iodideand the lead iodide according to a stoichiometric ratio, then placing in a DMF solution, magnetically stirring, taking the stirred solution, performing spin coating, drying, and scraping to collect powder, namely CH3NH3PbI3; then weighing different proportions of CH3NH3I according to a stoichiometric ratio to obtain a final product, namely organic-inorganic perovskite red fluorescent powder. The red fluorescent powder is excited in a wide wavelength range of near-ultraviolet light, can emit red fluorescence, has the luminous intensity being at most 8 times higher than that of CH3NH3PbI3 when xis 0, and can be applied