ARI-MA: Design and Growth of High Density, Wide Band-Gap Semiconductor Materials

该项目研究了使用专门设计的用于高分辨率室温鉴定裂变材料发射的<s:1>射线的新材料。这一努力将提高具有相对较宽能量缺口的高密度重元素半导体的科学水平和知识体系。拟议的项目在本质上具有变革性的潜力，因为它将使用基于？维减少?共价框架。利用晶体生长技术，我们将生长和调查各种半导体化合物，以验证它们的能隙和电阻率。为了允许施加更大的偏置，所需材料的最小室温电阻率需要达到~108欧姆-厘米，从而导致更快的载流子漂移速度和更深的探测装置损耗深度。对于最高Z的材料，所谓的Fano噪声也可以大幅降低（从而提高能量分辨率），通过选择化合物，如本文提出的硫族化合物。这些材料将以晶体和器件形式进行表征和测试，用于<s:1>射线检测。基于理论的材料设计将在很大程度上依赖于基于知识的高Z宽间隙半导体理想性能的优化。选择过程和实验方法也将密切依赖于理论指导。这是综合、测量和理论之间的密切跨学科合作，涉及具有互补技能的小组。

This project investigates the use of novel materials specially designed for high resolution room-temperature identification of ã-rays emitted from fissile materials. This effort will enhance the state of the science and body of knowledge for highly dense, heavy element semiconductors with relatively wide energy gaps. The proposed project has the potential to be transformative in nature because it will identify new materials for sensitive ã-ray detection using a new idea for materials design based on the concept of ?dimensional reduction? of covalent frameworks. Using crystal growth techniques, we will grow and survey a variety of semiconducting compounds to validate their energy gaps and their resistivity. A minimum room temperature resistivity of ~108 Ohm-cm is required in the desired materials in order to allow for larger biases to be applied, resulting in faster carrier drift velocities and deeper depletion depths in the detection device. For the highest Z materials, the so-called Fano noise can also be substantially decreased (and thus energy resolution improved), by choosing compounds such as the chalcogenides proposed here. The materials will be characterized and tested in both crystal and device form for ã-ray detection. Theory-based materials design will depend strongly on knowledge-based optimization of the desirable properties of high Z wide gap semiconductors. The selection process and experimental approach will also rely closely on theoretical guidance. This is a close interdisciplinary collaboration between synthesis, measurement and theory involving groups with complementary skills.