Preparation And Properties Of The Novel Mechanoluminescence Materials

Mechanoluminescence?ML?materials,a type of phosphors,can convert the local mechanical energy into light emission with the application of various stresses,such as deformation,friction,impact,and vibration.As a category of ML materials,elasticomechanoluminescence?EML?materials present an accurate linearity of ML intensity against load in the elastic region,in addition to the mechano-optical conversion.EML materials has been recognized as a stress probe to monitor the two-dimensional stress distribution in artificial skin,engineering structure,and living body in view of the advantages of wireless,non-destructive,reproducible,real-time and reliable stress sensing.In particular,the ML sensors have been found that they can be used as self-powered luminescence sensors.In order to meet the need of ML materials in practical applications,the rare earth doped luminescent materials have been investigated in this paper.The results achieved in this paper are given as follows:?1?Phosphors with reddish orange mechanoluminescence Sr₃Al₂O₅Cl₂:Eu_0.01,Ce_0.005 has been prepared by a solid state reaction method.The afterglow spectrum of Sr₃Al₂O₅Cl₂:Eu_0.01,Ce_0.005 shows a broad band at 585 nm.The afterglow color is reddish orange.The addition of Ce³⁺increases the ML intensity of Sr₃Al₂O₅Cl₂:Eu_0.01 considerably.The formation of many traps may be responsible for this enhancement.?2??1?The Sr_1.97Si_1-xP_xO₄:Eu_0.01,Dy_0.02 yellow-green phosphors were synthesized by a solid state reaction.The phosphors have a broad band around 490 nm,which is assigned to the 4f⁶5d?4f⁷ emission for Eu²⁺.The afterglow spectra show that the phosphors are yellow-green.With increasing the amount of doping P³⁺up to 1%,the luminescent brightness and the ML intensity of the phosphor are better than others.?2?The Sr_1.97-xMg_xSi_0.99P_0.01O₄:Eu_0.01,Dy_0.02 phosphors were synthesized by a solid state reaction.The XRD,photoluminescence emission spectra,the decay curve,the TL curve and the ML curve of phosphors were investigated in detail.The phosphors emit luminescence which is assigned to the 4f⁶5d?4f⁷ transition of Eu²⁺.Further studies on Sr_1.97-xMg_xSi_0.99P_0.01O₄:Eu_0.01,Dy_0.02indicated that the luminescence,the decay curve,the TL curve and ML intensity were influenced by Mg/Sr ratio.With 5%Mg²⁺content,the Sr_1.92Mg_0.05Si_0.99P_0.01O₄:Eu_0.01,Dy_0.02phosphor has the strongest ML intensity.?3?The SBAO:Eu(Sr_0.975Ba_0.025Al_1.9925O₄:Eu_0.0075)green phosphor was synthesized by a solid state reaction.The sample emits green light,which is due to the 5d?4f transition of Eu²⁺.We successfully prepared luminescence films with different thicknesses.Under the same conditions,the ML intensity of luminescence films enhances with the increase of tension,and enhances with the increase of pressure speeds.When the tension is less than 10N,the luminescence films have obvious mechanical luminescence properties.