Luminescent Properties Of Al₂O₃:Mn⁴⁺ And ZrO₂:Ti⁴⁺ And ZrO₂:Re³⁺?Re=Eu,Yb?

Transition metal ions Mn⁴⁺activated aluminate and fluoride luminescence materials have good luminescent efficiency and stability and have been widely used in the LED field.However,it is still not very clear to recognize the action mechanism of electronic energy structure of dopants on the luminescence efficiency,which to a certain extent limits the development and application Mn⁴⁺luminescent materials.In order to understand the luminescence properties of 3d transition metals,this paper explores the luminescent behavior of 3d electrons in broad bandgap compounds and the basic phenomenon of the corresponding electronic structure by analyzing the simplest Ti⁴⁺ion with 3d⁰ configuration.Next,Mn⁴⁺with 3d³ electron configuration was also investigated.This article mainly investigated the optical performance of simple binary compounds?Al₂O₃ and ZrO₂?.The main content is as follows.?1?Firstly,Al₂O₃:Mn⁴⁺red phosphors were synthesized via high-temperature solid-state reaction.The excitation spectrum of Al₂O₃:Mn⁴⁺phosphors were located at 317nm and 480nm,corresponding to overlapping by charge transfer of O^2-?Mn⁴⁺and ⁴A₂?⁴T₁of Mn⁴⁺ion,and the transition ⁴A₂?⁴T₂ of Mn⁴⁺ion.The main emission which is located at 675nm is ascribed to the transition ²E?⁴A₂?3d?3d?of Mn⁴⁺ion.Next,the author tried different co-doping ions to improve the luminescence properties of the prepared Al₂O₃:Mn⁴⁺materials.The results showed that the emission intensity of the sample with co-doping of Mg and Mn is 3.3 times larger than that of the sample with single doping of Mn.Subsequently,the valence states of Mn in the prepared samples and the possible charge compensation mechanisms were discussed by XPS measurement.?2?Secondly,the author synthesized ZrO₂:Ti⁴⁺phosphors by high-temperature solid-state method and studied the luminescence properties.The results show that under the excitation of 278nm wavelength ultraviolet light,there is a broadband emission with the emission peak at 469nm.Moreover,the sample has a strong long afterglow phenomenon,which is generally related to the electron traps.In order to study the nature of specific electron traps that cause long afterglow phenomenon,the author used a thermoluminescence dosimeter to measure the thermoluminescence curves of the prepared ZrO₂:Ti⁴⁺samples,and thus confirmed the existence of three kinds of electron traps.Based on the analysis results,the author obtained the energy level diagram of ZrO₂:Ti⁴⁺.?3?Finally,in order to understand the electronic structure and doping influence of ZrO₂,the author determined the ground state energy levels of Eu and Yb ions through experiment and theoretical calculations.Chemical Shift Model was used to analyze and predict the ground state energy levels of bivalent and trivalent lanthanide rare earth ions,and the vacuum referred binding energy levels which are corresponding to the bottom of conduction band and the top of valence band.Research results will provide an important reference for the subsequent research and development of the luminescent materials such as transition metal ions doped ZrO₂.