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利用250 keV质子和4.5 MeV氪离子(Kr17+)辐照未掺杂GaAs,注量分别为1×10~(12)-3×10~(14) cm~(-2)和3×10~(11)-3×10~(14) cm~(-2),使用光致发光谱和拉曼散射谱分析表征。发光谱的结果表明,随着剂量增大,质子辐照后的CAs峰及其声子伴线逐渐减弱,913 nm处的复合缺陷峰则先增大后减小,此峰与材料制备时的Cu掺杂无关。Kr离子辐照后本征发光峰则完全消失。拉曼散射谱的结果表明,相比于质子辐照,Kr离子辐照后LO声子峰峰位向低频方向移动,出现非对称性展宽,晶体结构发生明显改变。质子和Kr离子辐照效应的差异是由于移位损伤相差至少三个量级造成的。最后采用多级损伤累积(Multi-step damage accumulation,MSDA)模型得到了材料内缺陷的演化过程,并很好地解释了随损伤剂量增大GaAs光学性能及晶体结构的变化趋势。
Undoped undoped GaAs was irradiated by 250 keV protons and 4.5 MeV krypton ions (Kr17 +) with fluence of 1 × 10 ~ (12) -3 × 10 ~ (14) cm ~ (-2) and 3 × 10 ~ 11) -3 × 10 ~ (14) cm ~ (-2), which was characterized by photoluminescence and Raman scattering spectra. The results of the emission spectra showed that the CAs peak and its phonon accompanying the proton irradiation gradually weakened with the increase of dose, and the composite defect peak at 913 nm firstly increased and then decreased. Cu doping has nothing to do. After Kr ion irradiation, the intrinsic luminescence peak disappeared completely. The results of Raman scattering spectra show that compared with the proton irradiation, the peak of the LO phonon moves to lower frequency after Kr ion irradiation, resulting in asymmetric broadening and a significant change in the crystal structure. The difference in the effects of proton and Kr ion irradiation is due to a shift in displacement of at least three orders of magnitude. Finally, the multi-step damage accumulation (MSDA) model was used to obtain the evolution of defects in the material, and a good explanation of the change of optical properties and crystal structure of GaAs with the dose of damage was well explained.