权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

CAREER: Optoelectronic Probes of Interlayer Electron-Hole Pair Multiplication in Atomic Layer Semiconductor Heterostructures

职业：原子层半导体异质结构层间电子空穴对倍增的光电探针

基本信息

批准号：
1651247
负责人：
Nathaniel Gabor
金额：
$ 54.18万
依托单位：
University of California-Riverside
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-06-01 至 2022-05-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1651247&HistoricalAwards=false
关键词：
CAREER Optoelectronic Probes Interlayer Electron

项目摘要

Non-Technical Description: Nearly all household and commercial solar energy panels employ photovoltaic devices. These devices operate through an important microscopic process: an individual particle of light (a photon) is absorbed to create an individual pair of charge carriers (an electron-hole pair). Electron-hole pairs are then separated and collected to generate power. The efficiency of a photovoltaic device is governed by a simple competition: light energy is either converted into waste heat or useful electronic power. Ultra-thin materials may tip the balance in this competition by simultaneously limiting heat generation, while increasing the electronic power. This project explores ultra-thin materials to understand a fundamental process known as electron-hole pair multiplication. In this process, an individual photon is converted into multiple electron-hole pairs, thus dramatically increasing the device efficiency. Understanding such processes, together with improved designs that push beyond the theoretical efficiency limits, is expected to have a broad significance with regard to designing new ultra-efficient photovoltaic devices. A synergistic project within this research is the integration of undergraduate education across all levels by introducing the growing importance of Data Science methods in fundamental research and applied science. A key aspect of this project focuses on facilitating scientific exposure to underrepresented groups through intensive training and development, as well as raising awareness of the opportunities for underrepresented groups in professional scientific careers.Technical Description: The principal investigator and his research team are investigating a novel class of ultra-thin semiconductor photocells, which may exhibit highly efficient interlayer electron-hole pair multiplication by a single photon. The research efforts are addressing several fundamental challenges: (1) control and enhancement of photocurrent power conversion efficiency due to electron-hole pair multiplication, (2) reduction of electronic and thermal energy dissipation through efficient charge carrier multiplication and collection, and (3) direct measurement of the dynamics of multiplied interlayer electron-hole pairs. To accomplish the research objectives, the team utilizes versatile optoelectronic methods and approaches to uncover new phenomena to advance the current state of nanofabrication, spatio-temporal spectroscopy and condensed matter measurements. By developing innovative nano-optoelectronic devices and utilizing ultrafast photoexcitation spectroscopies, the PI is exploring a highly efficient mechanism of light energy harvesting, in which energy relaxation occurs predominantly through the electronic degree of freedom. The multi-disciplinary research of this project has a potential to broaden the understanding of electron-hole pair behavior in quantum-confined materials and two-dimensional heterostructures, and to guide new design principles for next-generation photovoltaic devices.

非技术描述：几乎所有家用和商用太阳能电池板都使用光伏设备。这些设备通过一个重要的微观过程运行：单个光粒子(光子)被吸收以产生单独的一对电荷载流子(电子-空穴对)。然后，电子-空穴对被分离并收集起来以产生电力。光伏设备的效率取决于一个简单的竞争：光能要么转化为余热，要么转化为有用的电子动力。超薄材料可能会在这场竞争中打破平衡，因为它同时限制了发热量，同时增加了电子功率。这个项目探索超薄材料，以了解一种称为电子-空穴对倍增的基本过程。在这个过程中，单个光子被转换成多个电子-空穴对，从而极大地提高了器件的效率。了解这种工艺，以及超越理论效率限制的改进设计，预计将对设计新的超高效光伏器件具有广泛的意义。这项研究中的一个协同项目是通过引入数据科学方法在基础研究和应用科学中日益增长的重要性来整合所有级别的本科教育。该项目的一个关键方面是通过密集的培训和发展促进科学接触代表性不足的群体，以及提高对代表性不足群体在专业科学职业生涯中机会的认识。技术描述：首席研究员和他的研究团队正在研究一种新型的超薄半导体光电池，这种电池可能通过单光子进行高效的层间电子-空穴对倍增。这些研究工作正在应对几个基本挑战：(1)控制和提高电子-空穴对倍增的光电流功率转换效率，(2)通过有效的电荷载流子倍增和收集来减少电子和热能的消耗，以及(3)直接测量倍增的层间电子-空穴对的动力学。为了实现研究目标，该团队利用多种光电方法和途径来发现新的现象，以推进纳米制造、时空光谱和凝聚态测量的现状。通过开发创新的纳米光电子器件和利用超快光激发光谱，PI正在探索一种高效的光能收集机制，其中能量弛豫主要通过电子自由度发生。该项目的多学科研究有助于拓宽对量子受限材料和二维异质结中电子-空穴对行为的理解，并指导下一代光伏器件的新设计原则。