SEP: A Sustainable Pathway to Terawatt-Scale Solution-Processed Solar Cells from Earth Abundant Elements

SEP：利用地球丰富的元素生产太瓦级溶液处理太阳能电池的可持续途径

• 批准号: 1230615
• 负责人: Hugh Hillhouse
• 金额: $ 190万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1230615&HistoricalAwards=false
• 关键词: SEP; Sustainable; Pathway; Terawatt; Scale

The NSF Sustainable Energy pathways (SEP) Program, under the umbrella of the NSF Science, Engineering and Education for Sustainability (SEES) initiative, will support the research program of Prof. Hugh Hillhouse and co-workers at the University of Washington to develop new solar cell technology from earth abundant elements. A sustainable energy pathway must yield high-value energy products at or below the price from non-renewables, with a net environmental and societal impact that is known and benign, and at a scale sufficient to become a major contributor to worldwide energy production (terawatts). Based on crustal abundance of the elements, mineral production rates, cost of the mineral feed stocks, the material defect chemistry, stability of the material and likely p-n junctions, and the photovoltaic electricity generation potential, Cu2ZnSnS4 (CZTS) appears to be a most promising candidate for terawatt-scale low-cost solar energy harvesting. Here, we will use a rigorous life cycle assessment (LCA) to analyze the sustainability of CZTS solar cells and avoid indirect market effects that have plagued other large-scale energy production routes. The LCA will affect the synthetic routes to fabricating the devices and help steer a body of fundamental research focusing on: (1) Developing a fundamental understanding of defects at interfaces and their passivation by applying combinatorial surface treatments, state-of-the-art electrical scanning probe methods, photoluminescence, and ab initio calculations; (2) Exploring the possibility of using novel voltage-boosting electron-dopant Auger de-excitation processes in the buffer layer; (3) Pioneering a method to utilize the unique properties of graphene to create a field-effect back contact. Using this 3-terminal back-contact architecture, the back-surface field, for the first time, will be tuned. This extra degree of freedom will allow the effects of surface chemistry to be separated from Fermi level equilibration. The increase in efficiency that could be achieved would bolster this technology to a level that would be economically competitive with current non-sustainable approaches.In 2009 the National Research Council estimated that fossil fuel use accounts for $120B/yr in non-climate damages and 20,000 premature deaths in the U.S. As a result, the development of a sustainable energy pathway to low-cost solar cells from Earth abundant elements will have a substantial impact on the environment and human health. In addition, the solar cell market is predicted to reach $44B/yr by 2017, and currently, U.S. companies lead the world in manufacturing and technology development for thin film devices. Advances such as those being pursued by the SEP team could shift thin film technology into the lead of the solar cell market, and help U.S. companies secure a long-term leadership position. The project will also train a skilled set of scientists and engineers for this growing manufacturing sector who understand the necessity of sustainable processes and appreciate the collaborative interdisciplinary approaches needed to achieve them. The impact of the project will be broadened by efforts including: (1) setting up a new children's exhibit at the Pacific Science Center called Light Racing, (2) deploying experimental solar cell technologies at the new UW Solar Energy Testbed Facility; (3) staffing the SunDawg Solar Kiosk which will be viewed by thousands at University of Washington and Seattle sporting events, (4) increasing the already substantial effort the investigators have in undergraduate research experiences (70 long-term research projects with undergraduates in the last decade); (5) expanding a high-school outreach program that within the past two years has already resulted in greater than 20 classroom visits to Seattle high schools, reaching more than 800 students; and (6) supporting efforts to broaden participation working with the MESA outreach program to provide mentorship to underrepresented minorities. This project has the transformative potential to solve key fundamental and technological challenges that will enable a new sustainable energy pathway for thin film solar cells that have economic advantage over current technology and are competitive with utilizing fossil fuel resources. If successful, the project could transform the solar industry from one currently dominated by silicon solar cells that are manufactured overseas to a new technology based on copper, zinc, tin, and sulfur that are manufactured in the U.S.

NSF可持续能源路径(SEP)计划隶属于NSF科学、工程和教育促进可持续发展(SEES)计划，将支持休·希尔豪斯教授和华盛顿大学同事利用地球丰富的元素开发新的太阳能电池技术的研究计划。可持续的能源途径必须以非可再生能源的价格或低于非可再生能源的价格生产高价值的能源产品，具有已知和良性的净环境和社会影响，其规模必须足以成为全球能源生产的主要贡献者(太瓦)。根据元素的地壳丰度、矿物生产率、矿物原料的成本、材料缺陷化学、材料和可能的p-n结的稳定性以及光伏发电潜力，Cu2ZnSnS4(CZTS)似乎是最有希望的太瓦级低成本太阳能收集的候选材料。在这里，我们将使用严格的生命周期评估(LCA)来分析CZTS太阳能电池的可持续性，并避免困扰其他大规模能源生产路线的间接市场影响。LCA将影响制造器件的合成路线，并有助于引导一系列基础研究，专注于：(1)通过应用组合表面处理、最先进的电子扫描探针方法、光致发光和从头计算，对界面缺陷及其钝化有一个基本的了解；(2)探索在缓冲层中使用新型电压提升电子掺杂俄歇去激发工艺的可能性；(3)首创一种利用石墨烯的独特性质来创建场效应背接触的方法。使用这种三端子背接触结构，背表面场将第一次被调谐。这种额外的自由度将允许表面化学的影响与费米能级平衡分开。可能实现的效率提高将使这项技术达到与当前不可持续的方法在经济上具有竞争力的水平。2009年，美国国家研究委员会估计，化石燃料的使用每年导致美国1200亿美元的非气候损害和2万人过早死亡。因此，从地球上丰富的元素开发一条可持续的能源途径，获得低成本的太阳能电池，将对环境和人类健康产生重大影响。此外，太阳能电池市场预计到2017年将达到440亿美元/年，目前，美国公司在薄膜设备的制造和技术开发方面处于世界领先地位。SEP团队正在追求的进步可能会使薄膜技术成为太阳能电池市场的领先者，并帮助美国公司获得长期的领先地位。该项目还将为这一不断增长的制造业培训一批熟练的科学家和工程师，他们了解可持续工艺的必要性，并欣赏实现可持续工艺所需的跨学科协作方法。该项目的影响将通过以下努力扩大：(1)在太平洋科学中心设立一个新的儿童展览，名为光赛车；(2)在新的华盛顿大学太阳能试验床设施部署实验性太阳能电池技术；(3)为SunDawg太阳能亭配备人员，该亭将在华盛顿大学和西雅图体育赛事上被数千人观看；(4)增加研究人员在本科生研究经验方面已经做出的重大努力(过去十年中与本科生进行了70个长期研究项目)；(5)扩大高中外展计划，该计划在过去两年内已导致对西雅图高中的20多次课堂访问，惠及800多名学生；以及(6)支持扩大参与的努力，与MESA外展计划合作，为代表不足的少数族裔提供指导。该项目具有解决关键的基本和技术挑战的变革性潜力，将为薄膜太阳能电池开辟一条新的可持续能源途径，使其具有相对于当前技术的经济优势，并与利用化石燃料资源具有竞争力。如果成功，该项目可能会将太阳能行业从目前由海外制造的硅太阳能电池主导的行业，转变为基于美国制造的铜、锌、锡和硫的新技术。