EAGER: Plasmonic Wide Angle Light Concentrators for Bulk-Heterojunction Solar Cells

Pi：Yu，秋明提案编号：1346859机构：华盛顿大学标题：EIGER：用于体异质结太阳能电池的等离子体广角聚光器有机体异质结太阳能电池具有成本低、重量轻、柔性和大面积器件等潜在优势，可以用卷对卷印刷的方法制造。尽管有机BHJ太阳电池的功率转换效率(PCE)的提高最近取得了进展，但要发展高效率的太阳电池，特别是工作在宽光入射角度的太阳电池，必须取得根本性的突破。这个迫切的项目将探索在BHJ太阳能电池中集成新型等离子体广角聚光器作为透明电极的概念，以调节和增强透射光，以匹配在大范围入射角度下有源层中施主和受主的能带隙。采用电磁时域有限差分(FDTD)模拟方法对等离子体纳米结构进行合理设计，利用传输矩阵(TM)光学模型对整个器件结构进行设计，以确保有源层对光的最大吸收。所设计的等离子体纳米结构将通过纳米印迹方法在玻璃衬底上制备，这种方法可以扩展到低成本的卷到卷印刷方法。通过对光电流密度-电压曲线、反射光谱和紫外-可见吸收光谱、稳态和动态光致发光(PL)以及外量子效率(EQE)的实验测量，阐明了等离子体纳米结构诱导的远场光传输和近场电场增强对BHJ太阳电池性能的影响以及太阳能转换的基本物理过程。本工作的目的是通过电磁模拟和实验相结合的方法，从根本上了解等离子体纳米结构调谐BHJ太阳电池广角光吸收和增强电荷传输和收集的物理原理和过程。将等离子体广角聚光器作为透明电极集成到BHJ太阳电池中，将使人们能够(1)取代昂贵的ITO；(2)调谐和聚集远场传输光，以匹配有源层中施主和受主的带隙；(3)无需机械移动部件即可实现广角吸收；了解近场电场对激子产生和电荷分离、输运和收集的增强作用。利用等离子体纳米结构实现的广角聚光器将被开发并集成到有机BHJ太阳能电池中，以提高即使在大斜入射角下的太阳能转换效率。这项工作的基础研究和实验结果可以推广到指导其他类型的太阳能电池和新型光电子和等离子体器件的发展。来自女性等代表性不足群体的研究生和本科生将接受培训，并参与这一高度跨学科的研究项目。

PI: Yu, Qiuming Proposal Number: 1346859 Institution: University of WashingtonTitle: EAGER: Plasmonic Wide Angle Light Concentrators for Bulk-Heterojunction Solar CellsOrganic bulk heterojunction (BHJ) solar cells offer the potential advantages as low-cost, lightweight, flexible, and large area devices that can be fabricated in the roll-to-roll printing method. Despite the recent progress in the increase of power conversion efficiency (PCE) of organic BHJ solar cells, fundamental breakthrough has to be made in order to develop high efficiency solar cells especially those working for wide light incident angles. This EAGER project will explore the concept of integrating novel plasmonic wide angle light concentrators as transparent electrodes in BHJ solar cells to tune and enhance transmitted light to match the energy band gaps of the donor and acceptor in the active layer in a wide range of incident angles. Electromagnetic finite-difference time-domain (FDTD) simulations will be applied to rationally design the plasmonic nanostructures and the transfer matrix (TM) optical modeling will be used to design the entire device architecture to ensure the maximum light absorption in the active layer. The designed plasmonic nanostructures will be made on glass substrates via the nanoimprinting method which can be extended to the low-cost roll-to-roll printing method. The effects of far-field light transmission and near-field electric field enhancementinduced by plasmonic nanostructures on the performance of BHJ solar cells and the fundamental physical processes in solar energy conversion will be elucidated by conducting the experimental measurements on photocurrent density-voltage curve, reflectance and UV-Vis absorption spectroscopy, steady state and dynamic photoluminescence (PL), and external quantum efficiency (EQE). The objective of this work is to fundamentally understand the physical principles and processes governing the tuning of wide angle light absorption and the enhancement of charge transport and collection in BHJ solar cells by plasmonic nanostructures via a combined electromagnetic simulation and experimental approach.By integrating plasmonic wide angle light concentrators as transparent electrodes in BHJ solar cells, it will allow one to (1) replace the expensive ITO; (2) tune and concentrate far-field transmitted light to match the band gaps of donor and acceptor in the active layer; (3) enable wide angle absorption without mechanical moving parts; and (4) understand near-filed electric field enhancement on exciton generation and charge separation, transport and collection. A wide angle light concentrator enabled by plasmonic nanostructures will be developed and integrated into organic BHJ solar cells to enhance the solar energy conversion efficiency even at large oblique incident angles. The fundamental investigation and experimental findings from this work can be generalized for guiding the development of other types of solar cells and novel optoelectronic and plasmonic devices. Graduate and undergraduate students from underrepresented groups such as female will receive training and participate in this highly interdisciplinary research project.