Structure And Optical Properties Of Eu And Dy Doped Wide Band Gap Nitride Semiconductors

Co-doping wide bandgap materials with different rare earth ions is an interesting research subject from the fundamental point of view as well as with respect to applications in optoelectronic and quantum technologies,which has bright application prospect and high commercial value in many fields such as detector laser illumination display and dilute magnetic semiconductor.However,the luminescence intensity of rare earth ions doped nitride still needs to be improved,and the interaction between co-doped rare earth ions is not clear.In this thesis,a series of Ga N,Al N films with Dy single implanted and Eu,Dy co-implanted samples have been prepared by ion implantation.The optical and structural properties of the RE doped Ga N and Al N films were studied and main results as follow:1.XRD and Raman results showed that ions implantation lead to strain and radiation damage which increased with Dy³⁺implanted fluence and was followed by a saturation.These two substrates had similar situation,but Al N exhibited stronger ability to suffer radiation damage than Ga N due to its stronger bond cooperation.2.The luminescence properties and excitation mechanism of Dy³⁺doped in Al N and Ga N were studied by PL and CL.At same dose,the emission intensity of Dy³⁺doped Al N was obviously stronger than Ga N.We presumed that the difference between Ga N and Al N was mainly due to various bandgap width and defect types.The effectively excitation of Dy³⁺in Al N might owing to O-related defects.3.Co-doped Mg²⁺could effectively enhance Dy³⁺emission intensity,especially when the concentration of Mg²⁺was 5.5×10¹⁸ at/cm³,the Dy³⁺emission line was increased by about 4.5 times,which possibly be achieved by reducing the symmetry of the lattice environments of Dy³⁺optical centres.4.The interaction between Dy³⁺and Eu³⁺were investigated.It was found that there may be exit energy transfer pathway from Dy³⁺to Eu³⁺in Al N,and the method that regulated the luminescence chromaticity by adjusting the ratio of Dy³⁺and Eu³⁺was proved.But in Ga N,the energy transfer between these two rare earth ions was opposite to that in Al N and the electric dipole-electric dipole interaction was proved to be dominant.The above research shows that it is feasible to obtain light emission through Eu³⁺and Dy³⁺doped Ga N and Al N,especially the energy transfer between Eu³⁺and Dy³⁺provides a new idea for the development of novel nitride photoelectric materials.