Impact of Interfacial Contact Layers on Photon-to-Electron Conversion Loss in Organic Solar Cells

技术描述：界面接触层（ICLs）已被证明可以改善有机太阳能电池的性能和稳定性。然而，不同的ICL材料如何与不同的活性层材料起作用还不是很清楚，目前常用的ICL材料存在一些局限性和缺点。本项目主要研究有机太阳能电池中用于界面接触层的金属氧化物纳米颗粒的溶液合成，以及它们在影响电荷分离、传输和收集方面的作用的实验和模拟研究。该项目的合成部分旨在了解和改善溶液中特定活性层成分的金属氧化物纳米颗粒的物理和电子特性，以避免需要积极的后处理。除了材料表征外，通过器件测试和频域光谱研究了纳米颗粒作为ICL材料在光子到电子转换过程中的有效性，探测了电荷复合和输运动力学。为了更好地理解实验结果，我们采用了真实的蒙特卡罗器件模型来确定主要的载流子损耗机制。此外，现有的漂移扩散输运模型假设均匀产生，只适用于弱吸收体。在本项目中，集成了两个开源仿真代码来模拟多层太阳能电池中的漂移扩散输运。从这项跨学科研究中获得的知识有望提高我们对有机系统中光生载流子动力学的理解。非技术描述：该项目解决了能量收集和其他有机电子技术的需求，包括新材料，新的合成方法，以及表征技术和最先进建模的结合，以提高我们在能量收集过程中的知识。在这个项目中开发的计算机程序将对公众开放。除了研究生教育外，该项目还使达拉斯地区的高中生和本科生能够亲身参与，为美国年轻人提供接触科学、技术、工程和数学的机会。主要研究人员还参与了面向K-12学生的拓展活动，招募和保留女性和代表性不足的少数民族学生，并通过各种专业协会为更广泛的科学界服务。

Technical Description: Interfacial contact layers (ICLs) have been shown to improve organic solar cell performance and stability. However, how different ICL materials function with different active layer materials is not well understood, and the commonly used ICL materials today suffer from several limitations and drawbacks. This project focuses on solution synthesis of metal-oxide nanoparticles for interfacial contact layers in organic solar cells and on experimental and simulation studies of their role in affecting charge separation, transport, and collection. The synthesis component of the project aims to understand and improve the physical and electronic properties of the metal-oxide nanoparticles for specific active layer components in solution to avoid the need of aggressive post processing. In addition to materials characterization, the nanoparticles' effectiveness as ICL materials on the photon-to-electron conversion process is studied through device testing and frequency-domain spectroscopies, which probe the charge recombination and transport dynamics. To understand the experimental results, realistic Monte Carlo device modeling is employed to pinpoint the dominant charge carrier loss mechanism(s). Additionally, currently available drift-diffusion transport model assumes uniform generation, which is only applicable for weak absorbers. In this project, two open-source simulation codes are integrated to model drift-diffusion transport in multi-layer solar cells. The knowledge gained from this interdisciplinary research is expected to improve our understanding of photogenerated carrier dynamics in organic systems.Non-technical Description: The project addresses the needs of energy harvesting and other organic electronic technologies, including new materials, novel synthesis approaches, and a combination of characterization techniques and state-of-art modeling to improve our knowledge in energy harvesting process. The computer programs developed in this project are to be available to the public. In addition to graduate student education, the project enables hands-on participation of the Dallas-area high-school and undergraduate students, providing opportunities for US youngsters to approach Science, Technology, Engineering, and Mathematics. The principal investigators also participate in outreach activities to K-12 students, in recruitment and retention of women and under-represented minority students, and in serving the broader scientific communities through various professional societies.