Study On The Optical Properties Of GaAs And InGaN Irradiated By Energetic Ions

The GaAs,GaN and InGaN based on III-V semiconductor alloys is widely used in the field of optoelectronic devices and space solar cell with large band gap,high electron mobility and saturated electron velocity.In particular,InGaN has the advantages of continuous band gap in the range of the entire solar spectrum,which was broadly used in multi junction solar cells in the field.In these environments,the materials may be irradiated by energetic particles,which could change the original photoelectric properties.Therefore,it is of great significance to study the irradiation effect on the evaluation of the radiation resistance.In this work,Firstly,Semi-insulating GaAs were irradiated by 250-keV H⁺ and 4.5-MeV Kr17+ ions with fluences range respectively from 1×1012 to 3×1014 cm?2.Photoluminescence?PL?spectrum and Raman spectra were used to analyse the difference between light and heavy ion irradiation and the evolution of defects in the material.Secondly,GaN and In_xGa_1-xN?x=0.37,0.47?were irradiated by 5-MeV Xe20+.The fluences were from 3×1011 to 1×1013 cm^-2.PL spectrum was used to study on the variation of luminescence properties under heavy ion irradiation.Then the irradiated samples were annealed for 30 minutes at a temperature of 500?,and the recovery mechanism were analyzed.Thirdly,In_xGa_1-xN?x=0.37,0.47?were irradiated by 352.8-MeV Fe17+ with fluences range from 1×1011 to 1×1013 cm^-2.PL and Raman spectrum were used to analyze luminescence properties and crystal structures after irradiation.According to the above research,the following conclusions were obtained:1.PL spectrum shows that the intensity of CAs peaks and phonon replicas decreased with increasing fluence of H⁺ irradiation.The peak in 913 nm was increased at lower fluences and decreased at higher fluences.But all the peaks were completely disappeared by Kr17+ irradiation.The results of Raman spectra show that the longitudinal-optical?LO?phonon peak at 295cm-1 towards the low-frequency side and broadens its width asymmetrically by Kr17+ irradiation,while it has no obvious change by proton irradiation.2.After Xe ions irradiation,the PL intensity of GaN was significantly decreased with increasing doses,which was slowly decreased in In0.37Ga0.63 N.As the In0.47Ga0.53 N sample,the PL intensity first increased at low doses and then decreased at high doses.The luminescence properties have superior resistance against heavy ions irradiation with the higher content of In elements in In_xGa_1-xN alloys.After annealing,the PL intensity of In_xGa_1-xN?x=0.37,0.47?were significantly increased,while it had no obvious change in GaN.3.After irradiation with high energy Fe ions,Raman spectra indicates that the ionization loss of Fe ions does not cause significant structural damage to the materials.PL spectrum shows that the luminescence properties of In_xGa_1-xN?x=0.37,0.47?are significantly increased at higher irradiation dose.