GaN基PIN紫外探测器的质子辐照效应

摘要：制备了GaN基PIN结构紫外探测器。用能量为2MeV的质子对器件依次进行注量为5×1014cm-2和2×1015cm-2的辐照。通过测量辐照前后器件的I-V曲线和光谱响应曲线，讨论了不同注量的质子辐照对GaN基紫外探测器件性能的影响。I-V特性表明，辐照使器件的反向暗电流增大，正向开启电流减小，并减小了器件的响应率，使峰值响应波长向短波方向稍有移动。为分析器件的辐照失效机理，研究了质子辐照对GaN材料的拉曼散射谱(Raman谱)和光致发光谱(PL谱)的影响。拉曼散射谱表明，A1(LO)模式随辐照注量向低频移动，通过拟合A1(LO)谱形，得到辐照使材料的载流子浓度降低的结果。PL谱表明，辐照使主发光峰和黄光峰强度降低，并出现一些新的发光峰，分析认为这是由于辐照引起了N空位缺陷和其他一些缺陷的亚稳态造成。

Proton Irradiation Effect on GaN based PIN UV Detector

GaN based PIN UV photodetectors were irradiated at room temperature with 2MeV protons at fluences of 5×1014cm-2,2×1015cm-2.I-V characterization and response spectrum of the detectors were measured before and after irradiation to analyze the irradiation effect. Increase in the reverse dark current and decrease in the forward firing current were observed after proton irradiation. And then it was found that the responsivity was reduced obviously and the response spectrum shifted towards short wavelength slightly after irradiation. To analyze the proton irradiation effect on detectors the Raman and photoluminescence (PL) spectroscopy of GaN film irradiated with proton at fluences of 5×1014cm-2,2×1015cm-2 and 1×1016 cm-2 were measured. The Raman spectra showed the A1(LO) peak shifted with proton fluence. The carrier concentration obtained by curve fitting of the Raman data was found to decrease with the proton irradiation fluence. The PL spectra showed a quenching effect for the dominant peak and the yellow emission.