The Study On Luminescence Properties Of Supertetrahedral Mn²⁺-Containing Chalcogenide Nanoclusters

Semiconductor luminescence materials have attracted great attention in the past two decades due to their superior physical properties,extensive application and ambitious development prospect.More attention has been focused on the Mn²⁺-doped semiconductor materials based on the Mn²⁺-related stable emission characteristics,high photoluminescence quantum yield and large Stocks shift which can further reduce the self-absorption.Although most studies of Mn²⁺-doped semiconductors focused on the bulk and nanocrystals materials,how to regulate the doping concentration and accurate location of Mn²⁺ions in the host materials remains a big challenge.A better understanding of doped structures and dopant environment will make it possible to regulate the emission properties and establish structure-performance relationships.The current study on Mn²⁺-related emission from supertetrahedral metal chalcogenide nanoclusters with well-defined structure and relatively precise dopant position can facilitate deep understanding of the Mn²⁺-location-performance relationship,which cannot be easily observed in the other conventional Mn²⁺-doped II–VI semiconductor nanocrystal with a random distribution of dopants.This thesis aims to utilize the supertetrahedral metal chalcogenide nanoclusters as the object of study,and focus on the exploration of the influence of dopant environment on the optical properties of those Mn²⁺-doped semiconductors,and make a deep understanding of the Mn²⁺-location-performance relationship.The main works are summarized as follows:?1?We realized the ordered distribution of Mn²⁺in the isolated T4 semiconductor nanocluster via in-situ synthetic strategy,and explored the influence of coordination environment and Mn???Mn interactions on the optical properties.The dopant concentration and location can be tuned by the control of adding doses of Mn²⁺.The precise position of Mn²⁺ions in such crystal lattice and its coordination environment are demonstrated to play a vital role in the understanding of the direct and subtle correlation between Mn²⁺-related emission and its corresponding structure.And it will provide a good theoretical foundation to tune the Mn²⁺-related emission.?2?Two new crystalline semiconductor materials containing Mn²⁺ions were obtained via the solvothermal method,in which T4 supertetrahedral metal chalcogenide nanoclusters serving as the basic building units are assembled into two-dimensional or three-dimensional structure,rather than being in the isolated form.The effect of the coordination environment of the Mn²⁺ions on the fluorescence properties in the multidimensional system was studied.The current research will provide a solid theoretical guidance for regulating the fluorescence properties of Mn²⁺-containing semiconductor materials in the fields of materials chemistry and photochemistry,and is expected to make significant contribution in the field of synthesis of new semiconductor materials.