Perovskite-type Layered Solid Template To Prepare Sulfide Semiconductor Nanomaterials,

Due to their nano-size structures (1-100 nm), semiconductor nanomaterials exhibit unique physical and chemical properties that differ from those of the bulk and the isolated ion or molecule system. The semiconductor nanoparticles can also be assembled into a two-dimensional structure, which could be a potential way to construct novel optoelectronic devices and shows fascinating applications in the electronic and optical field. There are three main experimental studies included in this dissertation.In the first part, layered metal halide perovskite solid templates are constructed by LB technique and their effect on metal sulfides' morphologies are also investigated. We study systemically on the control of the surface pressure change, the species of the inorganic metal ions, the existence of functional groups in organic amine and the introduction of small molecule materials, which may influence the properties of the template. Surface-area isotherm curve, UV-visible absorption spectrum, quartz crystal microbalance, X-ray diffraction, and transmission electronic microscope methods are used to characterize the structure change of the template before and after reaction with H₂S gas and the products' morphologies and properties. According to the obtained data, a possible control mechanism is proposed.Under lower surface pressure, molecules in LB films are not arranged closely, so the template is less ordered. With the increasing of the surface pressure, area per single molecule at air/water interface is reduced, and molecules arrange themselves closely with higher order. Perovskite solid template can be obtained at higher surface pressure via LB vertical lifting technique. Owing to different microenvironments in the template, reacting the PbCl-based perovskite template obtained at different surface pressure with H₂S gas, will result in amorphous, rod-like, cubic and disk-like nanomaterials. In this process, the amines act both as structure directing agents and surface passivation agents.Because of the difference of the inorganic layer structure, the above-mentioned...