NIRT: Photovoltaic devices based on semiconductor nanoparticles and nanowires

NIRT：基于半导体纳米颗粒和纳米线的光伏器件

• 批准号: 0506672
• 负责人: Eray Aydil
• 金额: $ 100万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-15 至 2011-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0506672&HistoricalAwards=false
• 关键词: NIRT; Photovoltaic; devices; based; semiconductor

ABSTRACT - 0506672University of Minnesota - Twin CitiesThe amount of energy incident onto Earth from our sun is so large that covering only 0.1% of the earth's surface with solar cells that are 10% efficient could generate enough power to meet the current demands of the world's population. However, harnessing this energy with inexpensive materials and low cost manufacturing technologies remains an important challenge. While steady progress has been made in solar cells based on the p-n junction diode, the cost of producing electricity from sunlight is still 4-5 times more expensive than competitive technologies. The availability of sustainable and inexpensive energy sources strongly influences the quality of human life. For this reason, new developments in solar-toelectric conversion methods would impact everyone's lives.We propose to establish an interdisciplinary research team that will focus on assembly and characterization of quantum-dot sensitized solar cells (QDSSCs) as well as on synthesis and characterization of its components. The QDSSC photoelectrode will be a macroscopic ensemble of 1-10 nm diameter semiconductor nanoparticles (e.g., CdSe, CdS, PbSe and Si ) attached to the periphery of 10-100 nm diameter wide band gap (ZnO and TiO2) semiconducting nanowires grown on a transparent conducting substrate. A thin layer of liquid electrolyte containing a redox couple will be sandwiched between this photoelectrode and a counter electrode to form the QDSSC. The macroscopic ensemble of nanometer size heterointerfaces between semiconducting nanoparticles and nanowires presents significant advantages both for light absorption and for charge separation, the two critical steps in solar-to-electric energy conversion. We propose to build solar cells that take advantage of (i) fast electron transfer across large interfacial areas, (ii) the ability to tune the absorption spectrum of nanoparticles to increase overlap with the solar spectrum and (iii) the possibility to generate multiple carriers per photon. This geometry is advantageous because photogenerated electrons in the smaller particle may be transferred to the wire and rapidly transported to a collection electrode while the hole is either transferred to an electrolyte or a hole conducting material. We propose to investigate (i) methods for synthesizing the components of the solar cell, (ii) methods for assembling these components into a functional device, and (iii) characterization of the solar cell, its components and the heterointerfaces, with particular emphasis on the interfacial electronic structure and electron transfer.Intellectual Merit - The scientific underpinnings of photovoltaic technology are multidisciplinary and cut across traditional boundaries between physics, chemistry, engineering and materials science. The proposed research brings together fundamental studies in synthesis and characterization of nanoparticles and nanosystems, and organizes these efforts in a common goal, discovery of novel efficient solar-toelectric energy conversion methods. To accomplish our goals, we bring together an interdisciplinary team of investigators with expertise ranging from synthesis and assembly of nanostructures (Aydil, Kortshagen, Norris) to materials, interface and photophysical characterization (Aydil, Zhu, Norris) and solar cell design and development (Aydil). The research activities in each of these areas have the potential to advance our knowledge and understanding in interfacial chemistry and physics of semiconductors as well as in synthesis of nanostructured materials. Furthermore, the combination of the advances in these individual fields has the potential to lead to novel solar cells that can reduce our dependence on fossil fuels and the negative effects of burning fossil fuels on the environment.Broader Impact - New developments in solar-to-electric conversion methods are of great interest to a wide scientific and non-scientific audience. Thus, the proposed project will not only have a broad impact but will also serve as an excellent vehicle for educating students and the general public; the project is a very concrete example of how nanotechnology can address one of the most pressing problems of the 21st century, availability of renewable energy. The PIs will supervise or co-supervise undergraduate students; host high school teachers, international visitors and faculty members from undergraduate institutions; visit high schools; and mentor students in university wide programs designed to increase the participation of disadvantaged or underrepresented groups in science and engineering. Specific examples of the PIs outreach activities are emphasized in Section 4, Results from Prior NSF Support. Such activities will continue with the present project.The proposed research addresses several of the eight high-risk/high-reward research and education themes outlined in the NSF-NSE announcement. In the order of priority these are (1)"Nanoscale Devices and Systems Architecture," (2) "Nanoscale Structures, Novel Phenomena and Quantum Control," and (3) "Manufacturing processes at the Nanoscale."

太阳照射到地球上的能量是如此之大，以至于只要覆盖地球表面的0.1%，用效率为10%的太阳能电池就能产生足够的电力，以满足目前世界人口的需求。然而，利用廉价的材料和低成本的制造技术来利用这种能源仍然是一个重要的挑战。虽然基于p-n结二极管的太阳能电池已经取得了稳定的进展，但利用太阳光发电的成本仍然是竞争技术的4-5倍。能否获得可持续和廉价的能源对人类生活的质量有很大的影响。由于这个原因，太阳能到电力转换方法的新发展将影响每个人的生活。我们建议建立一个跨学科的研究团队，专注于量子点敏化太阳能电池（QDSSCs）的组装和表征以及其组件的合成和表征。QDSSC光电极将是1-10 nm直径的半导体纳米粒子（例如，CdSe, CdS， PbSe和Si）的宏观集合，附着在10-100 nm直径的宽带隙（ZnO和TiO2）半导体纳米线的外围，生长在透明导电衬底上。在光电极和反电极之间夹上一层薄薄的含有氧化还原电偶的液体电解质，形成QDSSC。半导体纳米颗粒和纳米线之间的纳米尺寸异质界面的宏观系综在光吸收和电荷分离方面具有显著的优势，这是太阳能到电能转换的两个关键步骤。我们建议构建利用以下优势的太阳能电池：(1)大界面区域的快速电子转移；(2)调整纳米粒子吸收光谱以增加与太阳光谱重叠的能力；(3)每个光子产生多个载流子的可能性。这种几何结构是有利的，因为较小颗粒中的光生电子可以转移到导线上并迅速传输到收集电极，而空穴则转移到电解质或空穴导电材料上。我们建议研究(i)合成太阳能电池组件的方法，（ii）将这些组件组装成功能器件的方法，以及（iii）太阳能电池，其组件和异质界面的表征，特别强调界面电子结构和电子转移。知识优势——光伏技术的科学基础是多学科的，跨越了物理、化学、工程和材料科学之间的传统界限。该研究将纳米颗粒和纳米系统的合成和表征的基础研究结合在一起，并将这些努力组织在一个共同的目标中，即发现新的高效的太阳能到电力的能量转换方法。为了实现我们的目标，我们汇集了一个跨学科的研究团队，他们的专业知识范围从纳米结构的合成和组装（Aydil, Kortshagen, Norris）到材料，界面和光物理表征（Aydil, Zhu, Norris）以及太阳能电池的设计和开发（Aydil）。这些领域的研究活动都有可能促进我们对半导体界面化学和物理以及纳米结构材料合成的认识和理解。此外，这些单独领域的进步的结合有可能导致新的太阳能电池，可以减少我们对化石燃料的依赖和燃烧化石燃料对环境的负面影响。更广泛的影响-太阳能到电力转换方法的新发展引起了广泛的科学和非科学受众的极大兴趣。因此，建议的项目不仅会产生广泛的影响，而且还会成为教育学生和公众的绝佳工具；这个项目是纳米技术如何解决21世纪最紧迫的问题之一——可再生能源的可用性——的一个非常具体的例子。指导或共同指导本科生；接待高中教师、国际访问者和本科院校的教职人员；参观高中；并在大学范围内的项目中指导学生，这些项目旨在增加弱势群体或代表性不足群体在科学和工程领域的参与。在第4节，国家科学基金会先前支持的结果中强调了pi外展活动的具体例子。这些活动将在本项目中继续进行。拟议的研究涉及NSF-NSE公告中概述的八个高风险/高回报研究和教育主题中的几个。按优先顺序依次为(1)“纳米级器件和系统架构”，(2)“纳米级结构、新现象和量子控制”，以及(3)“纳米级制造工艺”。