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Study On Optical Properties Of Rare Earth Ion Doped Perovskite Quantum Dot Glass

Posted on:2024-03-29Degree:MasterType:Thesis
Country:ChinaCandidate:C T ZhouFull Text:PDF
GTID:2531307172481034Subject:Materials Science and Engineering
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Impurity doping is a promising method to change and improve the properties of materials.Since the 18th century,rare earth ions have been widely studied as highly efficient active dopants due to their unique optical,magnetic and electrical properties.Rare-earth doping can change the crystal structure phase,morphology and size,which leads to the adjustable optical response of doped nanomaterials.Therefore,a better understanding of the role of rare earth doping is a prerequisite for the development of inorganic nanomaterials.ABX3 perovskite has attracted extensive attention in recent years due to its excellent photoluminescence and photoelectric properties,such as high quantum yield,narrow emission bandwidth,large absorption coefficient and adjustable band gap.Unfortunately,the instability and poor water resistance of colloidal quantum dots synthesized by wet chemistry in air hinder their practical application.The effective way to solve this problem is to use a glass substrate to protect the quantum dots from decomposition.Borosilicate zinc glass is a potential candidate material because of its high temperature resistance and hardness.However,the fluorescence quantum yield of quantum dots in glass is greatly limited,so it is an urgent problem to improve the luminescence intensity of quantum dots in glass matrix.The five rare earth elements scandium(Sc),yttrium(Y),lanthanum(La),gadolinium(Gd)and lutetium(Lu)have relatively unique electron layer structure,showing relatively stable and non-luminous characteristics.In this context,the traditional melt quenching and heat treatment methods were used to synthesize the borosilicate zinc glass doped with five different rare earth ions Cs Pb I3quantum dots,which greatly improved the stability of perovskite quantum dots.In addition,the effects of the doping type and concentration of rare earth ions on the luminescence of perovskite quantum dots were further investigated by horizontal and longitudinal comparison.The main research contents of this paper are as follows:1.Cs Pb I3 quantum dot borosilicate zinc glass with scandium(Sc),yttrium(Y),lanthanum(La),gadolinium(Gd)and lutetium(Lu)doped with five ions of 0.1mol%was prepared by high-temperature melting quenching and heat treatment,and its influence on the luminescence properties of Cs Pb I3 perovskite quantum dots was investigated.The structure and optical properties of the prepared samples were analyzed by X-ray diffraction,infrared spectroscopy,Raman spectroscopy,light absorption,excitation emission spectroscopy and fluorescence lifetime.The results show that rare earth ions play a favorable role in the growth of quantum dots.On the one hand,they can promote the nucleation and growth of Cs Pb I3 quantum dots as nucleating agents.On the other hand,as the destruction agent of glass mesh,the density of glass mesh can be broken to reduce the generation energy of quantum dots,thus enhancing the red fluorescence intensity of Cs Pb I3.In addition,the size of rare earth ions also affects the nucleation and growth of quantum dots.According to the test results,we found that the Sc element rare earth ion with the smallest radius among the five ions selected is the best choice of doping type.Finally,a kind of light-emitting diode device is designed,which proves that the synthetic red glass powder has good performance and can play its potential application value in lighting and display.2.Using high temperature solid phase method and heat treatment means,rare earth ion scandium is used as dopant ion.Longitudinal study is made on the influence of scandium doping of different concentrations on the luminescence performance of Cs Pb I3.XRD,HRTEM and element Mapping showed that the size of Cs Pb I3quantum dots precipitated in the glass matrix was uniform and the number increased.Through a series of spectral tests,it was found that0.1mol%Sc3+was the optimal doping concentration,which could make the internal quantum yield of fluorescence reach the maximum of 35.68%reported so far.The stability test proves that the glass matrix can effectively protect the quantum dots from being decomposed by high temperature and water molecules.It is proved that this work has prepared stable red luminous materials with excellent luminous properties.Finally,a white LED device was constructed by coupling Sc3+-Cs Pb I3 QDs red glass powder with commercial green powder and blue chip.This provides a way to realize the potential application of Sc3+-Cs Pb I3QDs@glass in lighting field.
Keywords/Search Tags:Borosilicate zinc glass, Rare earth ions, Sc ion, Perovskite quantum dots, W-LED
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