CAREER:Engineering Efficient, Thin-film Hybrid Photovoltaic Elements Based on Excitonic Energy Transfer

这项研究的目标是设计一种新型的超薄、灵活、高效和坚固的光伏太阳能电池。这种方法是使用溶液可加工的半导体纳米晶体，通过化学方法将其嫁接到可电访问的柔性硅纳米管p-i-n结衬底上。智能优点：这些新型混合太阳能电池的设计基于无辐射和辐射能量转移，在高吸收纳米晶和三维结构的薄硅衬底之间提供了有效的电磁耦合。这种较长距离的能量转移机制基本上避免了导致传统体相异质结几何效率较低的典型电荷转移问题。具有工程设计的能量转移相互作用的光学厚度纳米晶体多层膜将被嫁接到从薄硅衬底加工的密集纳米微管阵列上，该阵列具有增强的光捕获能力和优化的p-i-n结，以实现高效的电荷分离和传输。这种纳米晶敏化硅太阳能电池的转换效率有望达到15%，所需硅材料最少。长远影响：薄而高效的光伏元件的开发应有助于减少我们对化石燃料的依赖，并有助于国内、环保和可再生能源发电技术和产业的发展。混合光电子学结构将对各种发光和传感器应用感兴趣，这种跨学科的方法将为学生提供机会，使他们精通光子学、材料科学、工程和物理领域，并与工业项目和国际合作者建立联系。将大力促进本科生和预科学生的参与，促进他们对科学和工程的兴趣。

The objective of this research is to engineer a new type of ultra-thin, flexible, yet efficient and robust photovoltaic solar cell. The approach is to employ solution processable semiconductor nanocrystals that are chemically grafted on electrically accessible, flexible Si nanopillar p-i-n junction substrates.Intellectual merit: The design of these novel hybrid solar cells is based on non-radiative and radiative energy transfer, which provides efficient electromagnetic coupling between highly absorbing nanocrystals and 3-dimensionally structured thin Si substrates. Such longer-range energy transfer mechanisms essentially avoid typical charge transfer problems leading to lower efficiencies of traditional bulk-heterojunction geometries. Optically thick nanocrystal multilayers with engineered energy transfer interactions will be grafted on dense arrays of nanopillars processed from thin Si substrates with enhanced light trapping capabilities and optimized p-i-n junctions for efficient charge separation and transport. Such nanocrystal-sensitized Si solar cells are expected to reach 15% conversion efficiency with minimal Si material requirements.Broader impacts: The development of thin, yet efficient photovoltaic elements should assist in lessening our reliance on fossil fuels and contribute towards the development of domestic, eco-friendly and renewable energy-generating technologies and industries. Hybrid optoelectronics structures will be of interest for various light-emitting and sensor applications and such interdisciplinary approach will provide students with an opportunity to gain proficiency in the fields of photonics, materials science and engineering and physics and to connect to industrial projects and international collaborators. Strong effort will be devoted to involve undergraduate and pre-college students and facilitate their interest in science and engineering.