离子辐照GaAs的光致发光和拉曼散射研究  

Study on photoluminescence and Raman scattering in GaAs by ion irradiation

作　　者：杨迪[1] 孙梦利 袁伟[1] 杜鑫[1] 彭海波[1] 王铁山[1] 郭红霞[2] 

机构地区：[1]兰州大学核科学与技术学院,兰州730000 [2]西北核技术研究所,西安710024

出　　处：《核技术》2016年第10期17-23,共7页Nuclear Techniques

基　　金：强脉冲辐射环境模拟与效应国家重点实验室(西北核技术研究所)专项经费资助项目~~

摘　　要：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。Background： GaAs is widely used as the second generation semiconductor material in the fields of aerospace and radiation detection.Purpose： Study of the irradiation effects of GaAs is of guiding significance for the evaluation of the radiation resistance of GaAs devices.Methods： Semi-insulating GaAs were irradiated by 250-keV H＋ and 4.5-MeV Kr17＋ ions with fluences ranging respectively from 1＆#215;1012 cm？2 to 3＆#215;1014cm？2 and 3＆#215;1011 cm？2 to 3＆#215;1014cm？2. Photoluminescence （PL） spectrum and Raman scattering spectra were used to measure GaAs samples before and after irradiation.Results： PL spectrum shows that the intensity of CAs peaks and phonon replicas decrease with increasing fluence of H＋ irradiation. TheIGa-VAs peak in 913 nm was increased at lower fluence and decreased at higher fluences. But all the peaks completely disappeared with Kr17＋ irradiation. The results of Raman spectra show that the longitudinal-optical （LO） phonon peak at 295-cm？1 slides towards the low-frequency side and broadens its width asymmetrically by Kr17＋ irradiation, while it has no obvious change by proton irradiation.Conclusion： The difference between the effect of proton and Kr17＋ irradiation is due to the difference of the displacement damage by three orders of magnitude at least. The evolution process of damage defects in GaAs is obtained by using Multi-step damage accumulation （MSDA） model, and then the trends of optical properties and crystalline structure are well explained.

关 键 词：辐照效应 光致发光谱 拉曼散射谱 

分 类 号：TL99[核科学技术—核技术及应用]