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

该项目研究使用专门设计的新型材料，在室温下高分辨率识别裂变材料发射的γ射线。这一努力将提高具有相对宽的能隙的高密度、重元素半导体的科学和知识体系。拟议的项目有可能在性质上是变革性的，因为它将确定新的材料敏感的射线探测使用新的想法，材料设计的基础上的概念？降维？共价框架。使用晶体生长技术，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。 在所需材料中需要约108 Ohm-cm的最小室温电阻率，以便允许施加更大的偏压，从而在检测器件中产生更快的载流子漂移速度和更深的耗尽深度。对于最高Z材料，通过选择诸如本文提出的硫属化物的化合物，也可以显著降低所谓的Fano噪声（并且因此提高能量分辨率）。材料将以晶体和器件形式进行表征和测试，以进行θ射线检测。 基于理论的材料设计将强烈依赖于基于知识的高Z宽禁带半导体的理想性能的优化。选择过程和实验方法也将密切依赖于理论指导。 这是合成，测量和理论之间的密切跨学科合作，涉及具有互补技能的团体。

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.