EAPSI: Fluid Flow-Assisted Assembly of Solar Cell Devices

有机光伏发电（OPVs）作为一种太阳能转换技术具有很大的前景，它可以很容易地大规模生产，而且价格便宜，可以提供与传统燃煤发电厂相当的电力。此外，柔性基板的使用潜力为太阳能电池与建筑和城市基础设施的整合提供了新的机会。虽然opv的优势很有吸引力，但该技术刚刚起步，尚未达到超过10%的功率转换效率。实现必要效率的大多数关键物理特性发生在由有机聚合物半导体组成的器件的有源层中。本项目旨在通过研究在分子尺度上控制活性层的组装和组织的好处来提高器件效率。该研究将在国立台湾大学吴志义教授的指导下进行，他在opv和类似半导体技术方面拥有丰富的经验，非常适合主持这项研究。OPV有源层中的关键过程包括通过光吸收产生的载流子和由于激子扩散、解离和向相反触点的输运而产生的载流子收集。激子吗?激发的，但仍然束缚的正负载流子对？与典型的固态光伏半导体中的电荷输运相比，有机材料具有相对较低的扩散长度和迁移率。因此，为了增加光子与材料的相互作用而增加有源层厚度的策略会由于载流子重组而导致效率损失，通常会使策略失效。年代的意图。一个这样的解决方案是增加有效的光学厚度，同时保持最小的物理厚度，通过集成金属纳米颗粒到聚合物基体。然而，像这样的溶液仍然经常通过旋转涂层沉积，这提供了对活性层厚度的良好控制，但对中尺度结构的控制很少。伊利诺伊大学厄巴纳-香槟分校最近的工作已经证明，由于微流体分子排列，有机半导体聚合物的光电性能得到了增强。本研究旨在通过微流控定向组装合成金属纳米颗粒掺杂，以达到前所未有的效率。该奖项由NSF与台湾科学技术部合作资助。

Organic photovoltaics (OPVs) hold great promise as a solar energy conversion technology which can be easily mass produced and is cheap enough to offer electricity at a price comparable to power generated from traditional coal-fired power plants. Furthermore, the potential for use with flexible substrates opens new opportunities for integration of solar cells with architecture and urban infrastructure. While the advantages of OPVs are attractive, the technology is just emerging from its infancy and has yet to reach power conversion efficiencies exceeding 10%. Most of the critical physics intrinsic to achieving the necessary efficiencies occur in the active layer of a device which is composed of organic polymer semiconductors. This project aims to improve device efficiency by investigating the benefits of controlling the assembly and organization of the active layer at the molecular scale. The research will be conducted under the mentorship of Professor Chih-I Wu at National Taiwan University who has extensive experience with OPVs and similar semiconductor technology and is ideally suited to host this research.Critical processes in the OPV active layer include charge-carrier generation through light absorption and charge-carrier collection due to exciton diffusion, dissociation, and transport to opposite contacts. Excitons?excited, yet still bound pairs of positive and negative charge carriers?in organic materials have relatively low diffusion lengths and mobilities compared to charge transport in typical solid-state photovoltaic semiconductors. As such, the strategy of increasing active layer thickness in order to increase photon interaction with the material leads to lost efficiency due to carrier recombination, often negating the strategy?s intentions. One such solution is to increase effective optical thickness while retaining minimal physical thickness by integration of metallic nanoparticles into the polymer matrix. Solutions such as this, however, are still often deposited by spin-coating, which provides excellent control of active layer thickness, but little control with regard to mesoscale architecture. Recent work at the University of Illinois at Urbana-Champaign has demonstrated enhancement of optoelectronic properties in organic semiconducting polymers due to molecular alignment via microfluidics. This research aims to achieve unprecedented efficiencies through the synthesis of metallic nanoparticle doping with microfluidic directed assembly. This NSF EAPSI award is funded in collaboration with the Ministry of Science and Technology of Taiwan.