The Preparation Of Porous Alumina Defective Photonic Crystals And Investigation Of Photoluminescence Enhancement

Since the concept of photonic crystals(PCs)was presented,the propagation of photons in periodic dielectric structures has attracted widespread attention from researchers.In many practical applications,the photons could be manipulated through photonic crystals with different defective states(DPCs).However,people are still facing difficulties in designing and preparing high quality defective photonic crystals with specific defective modes and transmission characteristics,such as the introduction of defective states and precise control of defective photonic band gap which is located in the visible-near infrared region,etc.The thesis firstly described the basic concepts,basic characteristics,and preparation methods of PCs and DPCs.Then,aiming at the above-mentioned problems,the author proposed to use a simple and controllable electrochemical anodization process to control the preparation of porous alumina defective photonic crystals,and to improve the quality of the samples by setting reasonable defective oxidation process parameters and introducing the voltage compensation mechanism;based on this,the author systematically summarized the research work on the theme of " The preparation of porous alumina defective photonic crystals and investigation of photoluminescence enhancement" during the Master's degree study.The main content could be divided into the following two aspects:1.A high quality porous alumina defective photonic crystals(DPCs)structure was successfully prepared with simple and controllable electrochemical anodizing process.By optimizing the design of periodic pulse anodization voltage waveform parameters and effective voltage compensation strategy,the band gap and defective mode quality of the obtained DPCs were further improved.The test results showed that by adjusting the key process parameters,the precise adjustment for the band gap and defective mode positions of the DPCs could be realized in the visible-near-infrared region.2.At the same time,rh B was introduced into the hole wall of porous alumina photonic crystals to form rh B/DPCs composite structure.The photoluminescence of the structure was systematically studied.The test results showed that the photoluminescence intensity of rh B was significantly enhanced when the blue edge of the defective photonic band gap and the defective mode position coincided with the emission peak of Rhodamine B,respectively.Therefore,it was experimentally confirmed that the photoluminescence effect of defective photonic band gap and defective mode on the luminescent material could be regulated by the drastic changes of the density of states at the edge and defective mode.Compare to the blue edge,the photoluminescence enhancement effect of the defective peak on rh B was more pronounced,reaching 3.1 times.The corresponding mechanism for photoluminescence enhancement was also discussed in detail.