EAGER: Engineering Defect Structure in Nanocrystalline Silicon: A Fundamental Study Using Scanning Probe Microscopy

这个探索性研究（EAGER）早期概念奖的目的是阐明导致氢化纳米晶Si （nc-Si:H）亚稳态的基本微观过程。氢化纳米晶硅（nc-Si:H）具有良好的光电性能，对经济高效的光伏和高性能光电器件具有重要意义。然而，使用现有技术生产的nc-Si:H的电学性能在光照射下由于产生亚稳缺陷而退化（光诱导降解）。这些缺陷的起源及其对纳米尺度光吸收和电荷输运的影响一直是人们争论的焦点。该研究将利用基于扫描探针显微镜的新型光电表征和通过晶体和非晶态区域的电荷传输的第一性原理模拟的独特组合来量化各种微观过程在亚稳性中的作用。如果成功，这一跨学科的合作将有助于开发高度稳定的nc-Si:H，可用于先进的太阳能电池设计。这项提议的努力将鼓励印第安人参与高等教育。美国原住民约占南达科他州人口的8.5%，吸引这个社区进入科技领域一直是一个挑战。SDSU的工程学院制定了一个积极的推广计划，以激励美国原住民高中生接受高等教育（SDSU- flandreau印第安学校成功学院）。该项目包括为美国土著高中生和中学生举办的太阳能研讨会。将开设光伏材料纳米成像的研究生课程，并加强研究生和本科生的多门课程。

The objective of this EArly-Concept Grant for Exploratory Research (EAGER) award is to elucidate the fundamental microscopic processes that are responsible for metastability in hydrogenated nanocrystalline Si (nc-Si:H). Hydrogenated nanocrystalline silicon (nc-Si:H) with improved optoelectronic properties is important for cost-effective photovoltaics and high-performance optoelectronic devices. However, the electrical properties of nc-Si:H produced using existing technologies degrade under light exposure (light induced degradation) due to the generation of metastable defects. The origin of the defects and their effect on light absorption and charge transport at the nanoscale has been under debate for a long time. The proposed study will utilize a unique combination of novel scanning probe microscopy-based optoelectronic characterization and first-principles simulation of charge transport through crystalline and amorphous regions to quantify the role of various microscopic processes underlying the metastability.If successful, this interdisciplinary collaborative effort will help develop highly stable nc-Si:H that can be incorporated into advanced solar cell designs. The proposed effort will encourage the participation of Native Americans into higher education. Native Americans represent about 8.5% of the population in South Dakota, and attracting this community into science and technology areas has been a challenge. SDSU's College of Engineering has developed an active outreach program to motivate Native American high-school students towards higher education (SDSU-Flandreau Indian School Success Academy). This project includes a workshop on solar energy for Native American high-school and middle-school students. A new graduate course in nanoscale imaging of PV materials will be developed, and multiple graduate and undergraduate courses will be enhanced.