Study On In³⁺,Si⁴⁺ Doped ZnGa₂O₄:Cr³⁺ Long Afterglow Materials

Long afterglow materials have broad application prospects in biomedicine,information storage and so on.Materials with blue,green and yellow afterglow in different systems have successfully prepared,and some of them with good long afterglow properties have met the requirements of practical applications.However,the red long afterglow materials are not ideal in terms of their luminosity and afterglow time.In this paper,In³⁺and Si⁴⁺ions are introduced into the Zn Ga₂O₄:Cr³⁺through high-temperature solid-phase reaction.Their luminescence and afterglow properties have been studied.This paper includes the following work:?1?In³⁺ions are introduced into the deep red emitting Zn Ga₂O₄:Cr³⁺by high temperature solid-state reaction method.XRD shows that In³⁺ions occupies the appropriate lattice position of Zn Ga₂O₄ and the doped In³⁺ions have not changed the basic structure of the host of Zn Ga₂O₄.The In³⁺ions doped change the local environment of Cr³⁺,however,causing that the strength of the ⁴A₂-⁴T₁ and ⁴A₂-4T₂transitions of Cr³⁺is significantly enhanced.The change of the coordination environment of Cr³⁺ions caused by doped In³⁺ions results in position difference of the Cr³⁺emission peak,so that the luminescence spectra show non-uniform broadening and the emission intensity of the sample is improved.It is found that Zn Ga2O4:Cr³⁺doped with 12%In³⁺presents the best photoluminescence properties and the Zn Ga₂O₄:Cr³⁺doped with 9%In³⁺have the best long afterglow properties in our experiment.It is also speculated that In³⁺ions may cause the decrease of the band gap of Zn Ga₂O₄.Consequently the sample can be excited by 455 nm blue light with lower energy than the ultraviolet light to produce afterglow phenomenon.?2?Si⁴⁺ions are introduced into the Zn?Bi?Ga₂O₄:Cr³⁺,In³⁺with deep red light luminescence by high temperature solid-state reaction method.The doped Si⁴⁺ions improve the afterglow brightness and prolong the afterglow time.Compared with Zn?Bi?Ga₂O₄:Cr³⁺,In³⁺,the fluorescence intensity of the Si⁴⁺doped sample is increased by 1.5 times.The afterglow intensity of the sample increases by 1.5 times after the excitation have stopped for 80 seconds.