Semi-insulating gallium arsenide (SI GaAs) detectors offer a promising alternative to commercially available silicon detectors. They demonstrate superior radiation hardness and provide improved efficiency for gamma and X-ray detection, primarily attributed to their higher density. In this study, we examined 350 μm thick SI GaAs detectors featuring front-side Ti/Pt/Au Schottky contacts with varying contact areas, complemented by back-side Ni/AuGe/Au ohmic contacts spanning the entire area. First, the reverse current-voltage characteristics of the prepared detectors were measured. The dependence of the reverse current and the breakdown voltage on the Schottky contact area was revealed. As the contact area decreases, the reverse current decreases and the breakdown voltage increases. The detection performance of the detectors was evaluated by alpha spectrometry using an ²⁴¹Am source. After irradiation of the detectors from the Schottky electrode, the measured alpha spectra show an increasing CCE with decreasing Schottky contact area. Finally, the correlation between the applied bias voltage and the extent of the active detector area from the edge of the detector contact was investigated.

中文翻译：

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α粒子半绝缘砷化镓探测器电场分布的实验分析

半绝缘砷化镓 (SI GaAs) 探测器为商用硅探测器提供了一种有前景的替代方案。它们表现出卓越的辐射硬度，并提高了伽马射线和 X 射线检测的效率，这主要归功于它们更高的密度。在这项研究中，我们检查了 350 μm 厚的 SI GaAs 探测器，该探测器具有不同接触面积的正面 Ti/Pt/Au 肖特基接触，并辅以覆盖整个区域的背面 Ni/AuGe/Au 欧姆接触。首先，测量所制备的检测器的反向电流-电压特性。揭示了反向电流和击穿电压对肖特基接触面积的依赖性。随着接触面积减小，反向电流减小，击穿电压增大。使用²⁴¹ Am 源通过 α 光谱法评估探测器的探测性能。在肖特基电极照射探测器后，测量的 α 光谱显示 CCE 增加，肖特基接触面积减少。最后，研究了所施加的偏置电压和有效检测器区域距检测器接触边缘的范围之间的相关性。