基于二维Ruddlesden-Popper型杂化钙钛矿太赫兹超材料的泵浦波长选择性调控机理及器件研究

目前，由于三维有机无机钙钛矿的光生载流子驰豫通道未能被有效限制，导致波长选择性调控太赫兹难以实现，严重制约太赫兹功能器件的发展和应用。本项目通过构建层状水平生长的二维Ruddlesden-Popper型杂化钙钛矿结构，利用其光生激子可量子隧穿超晶格进入半导体衬底形成自由载流子和光生自由载流子驰豫通道被有效限制的物理机制，实现光生激子吸收波长选择性调控太赫兹。本项目以(PEA)2(MA)n-1PbnI3n+1钙钛矿为研究对象，从钙钛矿制备出发，研究钙钛矿的层状生长方式和泵浦波长选择性调控太赫兹的物理机制，构建等效电路模型；研究不同泵浦条件下太赫兹钙钛矿超材料的波长选择性调控特性，并对优化结构进行加工和测试，进而构建钙钛矿超材料的设计规则和加工流程；在此基础上，探索基于泵浦波长选择性调控钙钛矿超材料的太赫兹功能器件。因此，研究成果对促进钙钛矿的激子性能研究和应用具有重要的理论和实际意义。

Currently, the wavelength selective controls of the terahertz radiations are difficult to realize because the relaxation channels of the photogenerated carrier in the 3D organic and inorganic perovskite can not be effectively constrained. These will severely restrict the developments and applications of the terahertz functional devices. In this project, two-dimensional ruddlesden-popper hybrid perovskite with the horizontal growth of layered structure are constructed. Based its physical mechanism in which the photogenerated excitons can tunnel the superlattice into the semiconductor substrate to form free carriers, and the relaxation channels of the photogenerated free carriers are effectively constrained, as a result, realizing photogenerated excitons absorption wavelength selective control of terahertz radiation. In the project, the (PEA)2(MA)n-1PbnI3n+1 perovskites are taken as the research object. Starting from the perovskite preparation, firstly, the growth mode of the layered structure and the physical mechanism of the pumping wavelength selective controlling terahertz radiations in the (PEA)2(MA)n-1PbnI3n+1 perovskites are studied to create the corresponding equivalent circuit model. Secondly, the wavelength selective control characteristics of the terahertz perovskite metamaterials under different pumping conditions are investigated. Then, the optimized structures are fabricated, tested and improved to building the design rules and fabrication procedures of the perovskite metamaterials. On this basis, finally, the terahertz functional devices based on the perovskite metamaterials with the pumping wavelength selective control characteristics are further explored. Therefore, the research results of this project have important theoretical and practical significance for promoting the study and application of the perovskite exciton properties.