Collaborative Research: Low Cost, High Performance Ultrathin GaAs Solar Cells for Terrestrial Photovoltaics

摘要：用于地面光伏发电的低成本、高性能超薄砷化镓太阳能电池非技术性：尽管砷化镓太阳能电池的性能令人印象深刻，接近理论极限，但其在地面应用中的实际应用仍然是一个艰巨的挑战，这主要是由于生长设备质量外延材料的成本过高。该提案中概述的研究旨在通过开发一种实用的解决方案来满足全球社会未来的能源需求，该解决方案可以平衡砷化镓太阳能电池的高性能与其生产成本，从而使其能够在地面光伏发电中大规模部署。拟议研究的高度多学科主题将与综合教学和推广工作紧密结合。 PI Yoon 将与南加州大学工程多样性中心合作，为洛杉矶市中心的教育弱势中学生和高中生建立实验室实习机会。 Co-PI Lee 将与耶鲁大学科学外展合作开展两个特别项目：面向家庭和公众的周六科学项目以及面向中学生和高中生的科学之路项目。培训本科生和研究生研究人员将是一个主要的教育目标，PI 将继续支持和鼓励扩大女学生和代表性不足群体学生的参与。技术：这项合作研究的目标是展示高性能、具有成本竞争力的砷化镓太阳能电池，以用于地面光伏发电的大规模部署。为了实现这一目标，我们将开发新的材料生长和器件制造策略，利用（1）超薄器件平台，能够有效利用昂贵的原材料，（2）多层外延生长，可以显着降低外延材料的成本，（3）双面纳米光子光操纵，可以增强吸收，（4）高产量印刷技术，允许在低成本基板上进行大面积分布。 具体来说，任务 1 将探索分子束外延 (MBE) 中超薄 GaAs 太阳能电池的多个器件堆叠的生长，目标是多层生长外延堆叠的均匀材料特性和器件性能。任务 2 将寻求建立对超薄 GaAs 太阳能电池外延设计的基本理解和优化，以增强载流子收集并最大限度地提高光捕获的有效性。任务 3 将重点开发用于光捕获和光子回收的双面光子管理综合方案。成功完成拟议的研究将有助于开发用于地面应用的高性能、经济可行的砷化镓太阳能电池，并加强对以下方面的基本理解：MBE 生长的多层外延组件中的材料行为和掺杂剂扩散；优化的超薄砷化镓太阳能电池层结构，实现最高效的光伏能量转换；多功能光学设计可最大限度地提高光学薄吸收体的光吸收率。

Abstract:Low Cost, High Performance Ultrathin Gallium Arsenide Solar Cells for Terrestrial PhotovoltaicsNontechnical: Despite their impressive performance reaching near the theoretical limit, the practical application of gallium arsenide solar cells in on-earth applications remains a formidable challenge largely due to the excessively high cost of growing device-quality epitaxial materials. The research outlined in this proposal aims to address the future energy demand of global society by developing a practical solution that can balance the high performance of gallium arsenide solar cells with their production cost, and therefore enable their large-scale deployment in terrestrial photovoltaics. The highly multidisciplinary themes of the proposed research will be intimately integrated with comprehensive teaching and outreach efforts. PI Yoon will work with the Center for Engineering Diversity at the University of Southern California to establish laboratory internship opportunities for educationally-disadvantaged middle and high school students in the inner city of Los Angeles. Co-PI Lee will partner with Yale Science Outreach on two particular programs: Science on Saturdays for families and the general public and the Pathways to Science program for middle and high school students. Training both undergraduate and graduate student researchers will be a primary educational goal, where the PIs will continue to support and encourage broadening participation of female students and students from underrepresented groups. Technical:The goal of this collaborative research is to demonstrate high performance, cost-competitive GaAs solar cells for their large-scale deployment in terrestrial photovoltaics. To achieve this goal, we will develop novel strategies of materials growth and device fabrication exploiting (1) an ultrathin device platform that enables efficient use of expensive source materials, (2) multilayer epitaxial growth that can significantly reduce the cost of epitaxial materials, (3) bifacial nanophotonic light manipulation that can enhance the absorption, (4) high yield printing techniques that permits large-area distribution over low cost substrates. Specifically, Task 1 will explore the growth of multiple device stacks of ultrathin GaAs solar cells in molecular beam epitaxy (MBE) targeting uniform materials properties and device performance of multilayer-grown epitaxial stacks. Task 2 will seek to establish fundamental understanding and optimization of the epitaxial design for ultrathin GaAs solar cells to enhance the carrier collection and maximize the effectiveness of light trapping. Task 3 will focus on developing integrated schemes of bifacial photon management for light trapping and photon recycling. Successful completion of the proposed research will lead to the development of high performance, economically viable GaAs solar cells for terrestrial applications and also strengthen fundamental understanding of: materials behaviors and dopant diffusion in MBE-grown multilayer epitaxial assemblies; optimized layer structures of ultrathin GaAs solar cells for the most efficient photovoltaic energy conversion; multifunctional optical designs for maximized light absorption in the optically thin absorber.