RII Track-4: Applying Transient Reflectance Spectroscopy to Decipher the Impact of Energetics and Electronic Coupling on Interfacial Recombination in Hybrid Halide Perovskites

RII Track-4：应用瞬态反射光谱破译能量学和电子耦合对混合卤化物钙钛矿界面复合的影响

• 批准号: 1929131
• 负责人: Kenneth Graham
• 金额: $ 17.92万
• 依托单位: University of Kentucky Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-02-15 至 2022-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1929131&HistoricalAwards=false
• 关键词: RII; Track; Applying; Transient; Reflectance

Hybrid organic-inorganic halide perovskites (HPs) are promising materials for use in next-generation solar cells and light-emitting diodes (LEDs). Further improvements in the performance and stability of these materials and devices will help enable mechanically flexible, lightweight, and inexpensive solar cells and LEDs that may be used in disaster relief areas, in military applications, and broadly deployed to help create a more secure and sustainable energy future. In both solar cells and LEDs, the HP is sandwiched between charge-transporting layers that serve to remove or inject charge carriers (either holes or electrons) into the HP. Interfaces between the HP and these transporting layers are the dominant areas where harmful non-radiative recombination processes occur, which can lower light generation efficiency and increase heat loss. Thus, it is essential to better understand these interfaces and identify means to reduce interfacial recombination rates. This research will directly probe recombination rates at HP interfaces with various transport layers using transient reflectance spectroscopy through a collaboration with Dr. Matthew Beard at the National Renewable Energy Laboratory (NREL). The Graham group has worked extensively on understanding and manipulating the surface chemistry of HPs. Through this grant, the Graham group will be able to directly probe how changes in surface chemistry impact interfacial charge recombination rates. The findings of this research will help accelerate the development of HPs for solar cells and LEDs, while the collaboration with NREL will help transfer knowledge from the nation's premier renewable energy research facility to researchers in Kentucky. Charge-transfer processes at interfaces are one of the most relevant processes determining the performance of electronic and optoelectronic devices, yet these interfacial processes remain much less understood than those occurring within the bulk of the materials. The goal of this proposed research is to use HPs as a platform to characterize how energetics and electronic coupling influence interfacial recombination processes through the application of transient reflectance spectroscopy. Transient reflectance relies on ultrafast laser pulses to monitor charge carrier recombination dynamics specifically at interfaces, thereby providing a powerful tool to differentiate interfacial recombination from recombination occurring within the bulk of the HP. Ultimately, the research will test the hypothesis that interfacial recombination rates can be significantly reduced through manipulating the interfacial energy landscape and electronic coupling at interfaces between dissimilar materials using surface modifiers. Previous research has investigated surface and bulk recombination in pure HPs in both single crystal and polycrystalline film formats, but these investigations have not been extended to include the presence of charge transport layers. Recombination rates have also been investigated within completed PV devices, but in these complete devices it is not possible to identify where recombination is occurring; thus, targeted approaches to reduce recombination are hindered. In this proposed research the principal investigator and a graduate student will work with Dr. Beard at NREL on applying transient reflectance spectroscopy to directly probe recombination rates at these important interfaces. Combining these transient reflectance measurements with ultraviolet and inverse photoelectron spectroscopy will uncover how interfacial energetics and electronic coupling impact interfacial recombination, thereby helping to guide the development of improved solar cells and LEDs based on HPs.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

杂化有机-无机卤化物钙钛矿（HP）是用于下一代太阳能电池和发光二极管（LED）的有前途的材料。 这些材料和器件的性能和稳定性的进一步改进将有助于实现机械灵活，重量轻，价格便宜的太阳能电池和LED，可用于救灾领域，军事应用，并广泛部署，以帮助创造一个更安全和可持续的能源未来。在太阳能电池和LED中，HP夹在电荷传输层之间，电荷传输层用于将电荷载流子（空穴或电子）移除或注入HP。 HP和这些传输层之间的界面是发生有害的非辐射复合过程的主要区域，这会降低光产生效率并增加热损失。 因此，有必要更好地了解这些接口，并确定减少界面复合率的方法。 这项研究将与国家可再生能源实验室（NREL）的Matthew Beard博士合作，使用瞬态反射光谱直接探测HP与各种传输层界面的复合率。 Graham小组在理解和操纵HPs的表面化学方面进行了广泛的工作。 通过这项资助，Graham小组将能够直接探测表面化学的变化如何影响界面电荷复合率。 这项研究的结果将有助于加速太阳能电池和LED的HP的开发，而与NREL的合作将有助于将知识从美国首屈一指的可再生能源研究机构转移到肯塔基州的研究人员。 界面处的电荷转移过程是决定电子和光电器件性能的最相关过程之一，然而这些界面过程仍然比材料本体内发生的过程少得多。 这项研究的目标是使用HP作为一个平台，通过瞬态反射光谱的应用来表征能量和电子耦合如何影响界面复合过程。瞬态反射依赖于超快激光脉冲，以监测电荷载流子复合动力学，特别是在接口，从而提供了一个强大的工具，以区分界面的复合发生在大部分的HP内的复合。 最终，该研究将测试的假设，界面复合率可以显着降低，通过操纵界面能量景观和电子耦合在不同材料之间的界面，使用表面改性剂。 以前的研究已经调查了表面和体复合在纯HP在单晶和多晶膜格式，但这些调查尚未扩展到包括电荷传输层的存在。 也已经在完成的PV器件内研究了复合率，但是在这些完成的器件中，不可能确定复合发生的位置;因此，减少复合的靶向方法受到阻碍。 在这项拟议的研究中，首席研究员和一名研究生将与NREL的Beard博士合作，应用瞬态反射光谱直接探测这些重要界面的复合率。 将这些瞬态反射率测量与紫外和逆光电子能谱相结合，将揭示界面能量学和电子耦合如何影响界面复合，从而有助于指导基于HPs的改进太阳能电池和LED的开发。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Photoactivated p-Doping of Organic Interlayer Enables Efficient Perovskite/Silicon Tandem Solar Cells

有机中间层的光激活 p 掺杂可实现高效的钙钛矿/硅串联太阳能电池

• DOI: 10.1021/acsenergylett.2c00780
• 发表时间: 2022
• 期刊: ACS Energy Letters
• 影响因子: 22
• 作者: Zheng, Xiaopeng;Liu, Jiang;Liu, Tuo;Aydin, Erkan;Chen, Min;Yan, Wenbo;De Bastiani, Michele;Allen, Thomas G.;Yuan, Shuai;Kirmani, Ahmad R.
• 通讯作者: Kirmani, Ahmad R.

Co-deposition of hole-selective contact and absorber for improving the processability of perovskite solar cells

• DOI: 10.1038/s41560-023-01227-6
• 发表时间: 2023-03
• 期刊: Nature Energy
• 影响因子: 56.7
• 作者: Xiaopeng Zheng;Zhen Li;Yi Zhang;Min Chen;Tuo Liu;C. Xiao;Danpeng Gao;Jay B. Patel;D. Kuciauskas;A. Magomedov;R. Scheidt;Xiaoming Wang;S. Harvey;Zhenghong Dai;Chunlei Zhang;D. Morales;Henry Pruett;Brian M. Wieliczka;Ahmad R. Kirmani;N. Padture;K. Graham;Yanfa Yan;M. Nazeeruddin;M. McGehee;Zonglong Zhu;J. Luther