CAREER: Strain Balanced Quantum Dots for High Concentration Solar Photovoltaics

技术：本职业奖的研究目标是解决未来高效太阳能电池的基础材料研究需求。虽然现有的研究表明纳米材料在提高太阳能电池效率方面的好处，但仍有大量的基础材料研究需要实际实施。例子包括选择合适的量子受限材料体系，研究外延纳米结构在太阳能器件中的生长和结合机制，以及光学和电学结果与理论预测的关系。此外，高浓度光伏系统必须在较高的工作温度下运行，因此纳米材料的降解机制是一个关键问题。该项目旨在研究以下基于材料的主题：1)使用点势垒应变平衡技术的III-V族量子点（QD）多层堆叠的气相外延生长和表征；2)利用光学和电学表征分析和证明量子点太阳能电池中真正的波函数重叠和小带形成；3)研究可变环境条件下量子点电池的降解机制。在以上所有内容中，重点放在理解量子点的高质量气相外延生长、纳米结构太阳能电池的光学和电学特性、基本量子力学预测和随后的载流子输运机制之间的相互作用。该项目利用了罗切斯特理工学院纳米能源研究实验室和美国宇航局格伦研究中心在纳米材料和太阳能电池开发方面的现有活动。非技术：该项目涉及材料科学主题领域的基础研究问题，具有高技术相关性。该项目的成功预计将对用于太阳能收集的纳米结构材料的进一步发展产生影响，总的来说，对纳米科学和纳米技术产生影响。该项目的研究和教育活动是一体化的。该项目培养纳米技术和光伏等新兴领域的博士和本科生。学生们有机会在美国宇航局格伦研究中心的光伏和电力技术分部度过暑假，学习纳米材料生长和最先进的太阳能电池表征技术的宝贵技能。从研究中获得的知识可以直接纳入开发下一代光伏的本科和研究生课程，从而使更多的学生参与可再生能源主题。除了教学方面，这个项目的成果计划通过出版物和与Emcore光伏和Spectrolab等公司的合作来传播。

Technical: The research objective of this CAREER award is to address the fundamental materials research need for future high-efficiency solar cells. While existing studies suggest benefits of nanomaterials in enhancing solar cell efficiency, there remains a significant amount of fundamental materials research necessary for practical implementation. Examples include selection of the appropriate quantum confined materials system, study of the growth and incorporation mechanisms of epitaxial nanostructures into solar devices, and relation of the optical and electrical results to theoretical predictions. Additionally, high concentration photovoltaic systems must operate under elevated operating temperatures, thus degradation mechanisms in nanomaterials is a critical issue. The project is designed to investigate the following materials based topics: 1) vapor phase epitaxial growth and characterization of multi-layer stacks of group III-V quantum dots (QD) using a dot-barrier strain balancing technique; 2) analysis and demonstration of true wavefunction overlap and miniband formation in quantum dot solar cells using both optical and electrical characterization, and 3) study of degradation mechanisms in QD cells under variable environmental conditions. In all of the above, emphasis is placed on understanding the interplay between high quality vapor phase epitaxial growth of the quantum dot, nanostructured solar cell optical and electrical characterization, fundamental quantum mechanical predictions and subsequent carrier transport mechanisms. This project leverages existing activities in nanomaterials and solar cell development at the Rochester Institute of Technology NanoPower Research Labs and NASA Glenn Research Center.Non-technical: The project addresses basic research issues in a topical area of materials science with high technological relevance. The success of the project is expected to have impacts on the further advancement of nanostructured materials for solar energy harvesting and, in general, nanoscience and nanotechnology. The research and education activities of the project are integrated. This project trains Ph.D. and undergraduate students in the emerging fields of nanotechnology and photovoltaics. Students have the opportunity to spend the summer at NASA Glenn Research Center's Photovoltaics and Power Technologies Branch, learning valuable skills involving nano-material growth and state-of-the-art solar cell characterization techniques. The knowledge gained from the research can be directly incorporated into developing both undergraduate and graduate level courses in next generation photovoltaics, thus involving an even lager body of students in renewable energy topics. Beyond the teaching aspect, the results of this project are planned to be disseminated through both publication and collaboration with companies such as Emcore Photovoltaics and Spectrolab.