Engineered 3D Material Matrices with Embedded Semiconductor Micro/Nano-pillars for Radiation Sensing

该奖项的研究目标是研究结合了高效电子-空穴对收集材料和辐射敏感材料的功能材料矩阵所实现的辐射传感机制。该方法基于半导体结光电探测器的制造，其形状为垂直取向的柱子，将嵌入功能辐射敏感材料（如富硼）中。建立探测效率与柱尺寸、柱间距离、表面平面度、柱与辐射传感材料界面最佳电荷传递的低阻接触等器件参数之间的关系。在不同的生长条件下，材料基体中的应变将被研究以最小化界面应力。该研究还将包括先进的表面钝化技术，如在柱探测器周围热液生长富集硼化合物，同时作为钝化涂层和中子敏感材料。这项研究的结果，如果成功，将导致高效率、轻量化、低成本和大面积的固态辐射传感器。这种设备将提供氦同位素的替代品，目前传统中子探测器中使用的氦同位素正面临着供应短缺的问题，此外还有诸如易受微音、高工作电压、高压和由于占地面积大而导致的现场性差等缺点。通过半导体行业使用的制造工艺的应用，该研究提供了实现新型先进辐射传感系统的潜力，该系统可以与高速读出电子设备集成，用于粒子物理、国土安全、防扩散、中子射线照相和材料表征。基于这项研究的教育和推广项目将扩大未被充分代表的群体在科学和技术领域的参与，并通过与国家实验室的积极合作培养未来的多学科科学家和工程师。

The research objective of this award is to study the radiation sensing mechanism enabled by functional material matrices that combine highly efficient electron-hole pair collecting materials with radiation sensitive materials. The approach is based on the fabrication of semiconductor junction photodetectors in the shape of vertically oriented pillars that will be embedded in functional radiation sensitive materials such as enriched boron. The relation between the detection efficiency and device parameters such as pillar dimensions, inter-pillar distances, surface planarity and low resistance contacts for optimum charge transfer at the interface of the pillars and the radiation sensing materials will be established. The strain present in the material matrices under different growth conditions will be studied to minimize the interface stresses. The study will also include advanced surface passivation techniques such as hydrothermal growth of enriched boron compounds around the pillar detectors to simultaneously act as passivation coatings as well as neutron sensitive materials.The outcome of this research, if successful, will lead to highly efficient, lightweight, low-cost and large area solid-state radiation sensors. Such devices will offer alternatives to helium isotopes that are currently being used in conventional neutron detectors and are facing a looming supply shortage, in addition to the disadvantages such as susceptibility to microphonics, high operational voltage, high pressure and poor fieldability due to large footprint. Through the applications of manufacturing processes used by the semiconductor industry, the research offers the potential to enable a new class of advanced radiation sensing systems that can be integrated with high-speed read-out electronics for applications in particle physics, homeland security, non-proliferation, neutron radiography and material characterization. Educational and outreach programs based on this research will broaden the participation of underrepresented groups in science and technology and train future multidisciplinary scientists and engineers through an active collaboration with the National Laboratories.