EAGER: Electrically pumped transient charge-carrier dynamics of metal halide perovskite light-emitting diodes

EAGER：金属卤化物钙钛矿发光二极管的电泵瞬态载流子动力学

• 批准号: 2222043
• 负责人: Barry Rand
• 金额: $ 13.49万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-05-01 至 2023-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2222043&HistoricalAwards=false
• 关键词: EAGER; Electrically; pumped; transient; charge

Metal halide perovskite light-emitting diodes (PeLEDs) hold potential for a new generation of display and lighting technology, featuring high color quality, energy efficiency and low manufacturing cost. Additionally, perovskites are deposited from solution, meaning that they can be deposited on virtually any substrate, including silicon. However, the slow operation speed of PeLEDs limits their potential for a wider scope of applications, such as interchip and intrachip optical communications, which are dominated by more expensive technologies using III-V semiconductors. In this project, the PI proposes to study transient charge-carrier dynamics of PeLEDs under ultrashort electrical excitation. If successful, the proposed investigation will advance the understanding of the intrinsic speed limitations in these materials, and can begin in earnest for less well developed aspects of halide perovskite optoelectronic applications, such as in optical communications integrated on-chip. Currently, such applications are restricted due to unknowns regarding perovskite LED switching speeds, and this proposed project will fill these knowledge gaps. The research will strengthen technological leadership of the U.S. and prepare the next generation of STEM graduates, including women and underrepresented groups, to follow a STEM career. The PI will continue to engage with the public and students, and is particularly involved in active learning activities to establish role models across generational gaps. At the undergraduate and graduate level, the PI will, via lectures, practical labs, research and courses, stress applications and the benefits of science on society and include guest lectures in order to inspire a new generation of STEM students and allow students to see the rewards of a STEM career.Probing transient charge-carrier dynamics in real devices is important to understand their operation mechanisms. However, reported studies on charge-carrier dynamics so far, as far as can be understood, have been constrained by optical pumping. No studies have ever been conducted to probe the transient charge carrier dynamics under electrical excitation, which is closer to the real device operation conditions. On the other hand, electrical excitation is considerably distinct from optical pumping, and this likely is due to interface or bulk electrochemical processes that couple transport equations with chemical processes. The proposed study will investigate transient charge-carrier dynamics of PeLEDs under ultrashort electrical excitation and investigate how additional electrochemical processes will cause the differences between optical and electrical pumping with respect to recombination processes. Then, the PI will investigate and understand how the various perovskite compositions will influence the transient charge-carrier dynamics under electrical pumping, and disclose dominant factors governing the transient device response and make faster PeLEDs possible. Two scientific goals that will allow for future applications are: 1) advancing the understanding of the intrinsic speed limitations in PeLEDs; 2) a better appreciation for differences between optical and electrical pumping with respect to recombination processes.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.

金属卤化物钙钛矿发光二极管（PeLED）具有高色彩质量、高能效和低制造成本的特点，有望成为新一代显示和照明技术。此外，钙钛矿从溶液中沉积，这意味着它们可以沉积在几乎任何衬底上，包括硅。然而，PeLED的缓慢操作速度限制了其更广泛应用的潜力，例如芯片间和芯片内光通信，这些应用由使用III-V族半导体的更昂贵的技术主导。在这个项目中，PI建议研究超短电激励下PeLED的瞬态电荷载流子动力学。如果成功的话，所提出的研究将促进对这些材料中固有速度限制的理解，并且可以开始认真地用于卤化物钙钛矿光电应用的欠发达方面，例如在光通信集成芯片中。目前，由于钙钛矿LED开关速度的未知因素，此类应用受到限制，而该项目将填补这些知识空白。该研究将加强美国的技术领导地位，并为下一代STEM毕业生（包括女性和代表性不足的群体）做好准备，以从事STEM职业。PI将继续与公众和学生接触，特别是参与积极的学习活动，以建立跨越代沟的榜样。在本科生和研究生阶段，PI将通过讲座、实践实验室、研究和课程，强调应用和科学对社会的好处，并包括客座讲座，以激励新一代STEM学生，让学生看到STEM职业的回报。探测真实的设备中的瞬态电荷载流子动力学对于理解它们的运行机制非常重要。然而，迄今为止，据了解，关于电荷载流子动力学的报道研究受到光泵浦的限制。还没有进行研究来探测电激励下的瞬态电荷载流子动力学，这更接近于真实的器件操作条件。另一方面，电激发与光泵浦有很大的不同，这可能是由于耦合传输方程与化学过程的界面或体电化学过程。拟议的研究将调查在超短电激发下PeLED的瞬态电荷载流子动力学，并调查额外的电化学过程将如何导致光和电泵浦之间的差异，相对于复合过程。然后，PI将研究和了解各种钙钛矿组合物如何影响电泵浦下的瞬态电荷载流子动力学，并揭示控制瞬态器件响应的主导因素，使更快的PeLED成为可能。两个科学目标，将允许未来的应用是：1）推进PeLED的内在速度限制的理解; 2）更好地欣赏之间的光和电泵浦相对于复合过程的差异。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。