From Gallium-based Supramolecular Nanomaterials To ?-Ga₂O₃ Nanolayers With High Solar-Blind Detection Performance

Solar-Blind Detection(SBD)system has been paid more and more attention in civil and military fields.?-Ga2O3 possessing wide band gap and good stability.The research of its nanomaterials will be an important development direction of building gallium oxide solar-blind detector in the future,and it has considerable application potential in the SBD system.In order to solve the problem of solvent interference in the preparation of ?-Ga2O3 nanocrystals,the supermolecular nanocrystals of gallium-based complexes were constructed by solid-state grinding at room temperature.On the basis of understanding the temperature/structure dependence of precursors,high-quality ?-Ga2O3 nanocrystals were synthesized by controlled pyrolysis of precursors,and the solar-blind detection performance of ?-Ga2O3 nanocrystals was upgraded.Finally,a solar blind detector with excellent photoelectric response performance is constructed.Based on the solid-state reaction at room temperature,the preparation of metal oxide nanocrystals by constructing/destructing supermolecular nanocrystals is novel and original.The formation of nano-supramolecular inclusion complex can not only significantly change the host cavity microenvironment,but also fine-tune the structure or performance of the specific guest.This method not only has low cost competitive edge,such as simple and efficient,no harsh reaction conditions,no solvent,etc.It also has a large-scale application prospects such as the synthesis of other metal-based supramolecular nanomaterials and metal oxide nanomaterials.We believe that the grinding-pyrolysis strategy provides an efficient and convenient way to synthesize high-quality supramolecular nanocrystals and inorganic nanomaterials.There are three aspects in this thesis:1)the green synthesis of ?-Ga2O3 nanolayer;2)the fabrication of metal oxide materials with nano-supramolecular materials;3)the research on the solar-blind detection performance of ?-Ga2O3 materials.The first part contains the following contents:a simple grinding method is used to prepare supramolecular square nano-plates formed by cyclodextrin and gallium acetylacetone.The nanoplates exhibit highly monodisperse distribution at room temperature and form supramolecular lamellar nano-sheets at 353 K by self-assembly.When heated to a higher temperature such as 673 K lamellar nano-slice decomposes into ?-Ga2O3 laminate.Compared with ?-Ga2O3 with three-dimensional structure,?-Ga2O3 nanoparticles(about 15 nm thickness)have very high specific surface area(93.9 m2·g-1).The second part includes the following contents:the strategy of fabricating supramolecular crystals by solid-state grinding and then deconstructing oxide nanomaterials is extended to the controllable synthesis of other metal-based supramolecular nanocrystals.The feasibility of using other guest instead of metal complex GAA and other host to replace ?-CD was demonstrated.The third part contains the following contents:the photoluminescence properties and SBD performance of y-Ga2O3 with two different structures formed by the supramolecular path and the gallium complex path are compared.The former shows better performance of solar-blind detection(larger light-dark current ratio;faster response time;better photocurrent stability).