Enhanced Photon-Electron Conversion in Thin Film Solar Cells by Propagating Surface Plasmons

通过传播表面等离子体激元增强薄膜太阳能电池中的光子-电子转换

• 批准号: 1408025
• 负责人: Jung-Kun Lee
• 金额: $ 32.52万
• 依托单位: University of Pittsburgh
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1408025&HistoricalAwards=false
• 关键词: Enhanced; Photon; Electron; Conversion; Thin

Several types of thin film solar cells have recently drawn a great amount of attention, due to its huge potential in solar energy harvesting. However, the energy conversion efficiency of the well-known solar cells is still far from the theoretical expectation. The low efficiency is due to inefficient light absorption by the semiconductor and limited carrier extraction from the semiconductor to the external load. These two factors are closely related, which makes the development of a solution more difficult. Development of the thin film solar cells using the surface plasmons of the nanostructures will address this difficult problem and contribute to furthering the goal of energy security of the US. Given that the electricity produced from solar radiation is only about 1% of the total annual electricity consumed in the US, the success of this research will contribute to increasing US's energy security by providing highly efficient thin film solar cells. The integration of the anticipated research accomplishments with existing and new classroom courses will also improve the quality of engineering education on nanoscience and renewable energy at the University of Pittsburgh. In addition, the multi-disciplinary nature of the project will provide undergraduate and graduate students with the opportunity to be exposed to new frontiers in design, fabrication and characterizations of materials and devices, beyond the boundaries of their disciplines. Finally, this project will be aimed at using research products such as thin film solar cells to reach underrepresented groups, which will be coordinated with on-going efforts of the University of Pittsburgh to expand the participation of underrepresented groups in engineering education. Current problems associated with the thin film solar cells clearly show a strong need for design of a new nanostructure that can enhance the light absorption and carrier transport in the thin film semiconductor. One very promising way is to exploit resonance phenomenon, such as surface plasmons. However, popular plasmonic metal nanoparticles have several drawbacks to be implemented to the thin film solar cells. In this project, a propagating surface plasmon on 1-dimensional photonic crystal/metal thin film interface will be used to circumvent the problems of the metal nanoparticles. The new nanostructure will increase the light harvesting efficiency without increasing the thickness of the semiconductor film (i.e. decreasing the carrier collection efficiency). The objective of this project is to fabricate a new junction-type thin film solar cell employing the photonic crystal based plasmonic nanostructure and to explore the physical interactions among propagating surface plasmons, solar light modulation, and carrier/exciton generation. Progress of the research will create the fundamental understanding of the photon-exciton conversion under the influence of the surface plasmons for the thin film solar cells. For this purpose, the nanostructured photonic crystal will be designed to excite the surface plasmons that interact with incoming solar light in a visible range. In addition, basic understanding of light-matter interactions and radiative properties of nanostructures will be pursued. The intellectual significance of this project is that new directions for highly efficient hybrid solar cells will be provided. Knowledge on surface-plasmon-assisted tuning of the light absorption will facilitate a new class of photovoltaics which is not limited by the tradeoff between light absorption and carrier transport.

由于其在太阳能收集方面的巨大潜力，几种类型的薄膜太阳能电池最近引起了人们的广泛关注。然而，众所周知的太阳能电池的能量转换效率与理论预期仍相距甚远。 效率低是由于半导体的光吸收效率低以及从半导体到外部负载的载流子提取有限。 这两个因素密切相关，这使得解决方案的开发变得更加困难。利用纳米结构的表面等离子体激元开发薄膜太阳能电池将解决这一难题，并有助于进一步实现美国能源安全的目标。 鉴于太阳辐射产生的电力仅占美国每年总电力的1%左右，这项研究的成功将通过提供高效薄膜太阳能电池为提高美国的能源安全做出贡献。 将预期研究成果与现有和新的课堂课程相结合也将提高匹兹堡大学纳米科学和可再生能源工程教育的质量。此外，该项目的多学科性质将为本科生和研究生提供超越其学科界限，接触材料和设备的设计、制造和表征新领域的机会。最后，该项目旨在利用薄膜太阳能电池等研究产品来惠及代表性不足的群体，这将与匹兹堡大学正在进行的努力相协调，以扩大代表性不足的群体对工程教育的参与。当前与薄膜太阳能电池相关的问题清楚地表明，强烈需要设计一种新的纳米结构，以增强薄膜半导体中的光吸收和载流子传输。 一种非常有前途的方法是利用共振现象，例如表面等离子体。然而，流行的等离激元金属纳米粒子在薄膜太阳能电池中应用时存在一些缺点。 在该项目中，一维光子晶体/金属薄膜界面上的传播表面等离子体将用于规避金属纳米粒子的问题。 新的纳米结构将在不增加半导体薄膜厚度（即降低载流子收集效率）的情况下提高光捕获效率。 该项目的目标是制造一种采用基于光子晶体的等离子体纳米结构的新型结型薄膜太阳能电池，并探索传播表面等离子体、太阳光调制和载流子/激子生成之间的物理相互作用。 该研究的进展将为薄膜太阳能电池在表面等离子激元影响下的光子-激子转换提供基本的理解。 为此，纳米结构光子晶体将被设计为激发与可见光范围内的入射太阳光相互作用的表面等离子体。 此外，还将追求对光与物质相互作用和纳米结构的辐射特性的基本了解。 该项目的智力意义在于将为高效混合太阳能电池提供新的方向。 关于表面等离子体辅助光吸收调节的知识将促进新型光伏发电的发展，这种光伏发电不受光吸收和载流子传输之间权衡的限制。