MRI: Development of an Ultrafast Photoluminescence and Transient Absorption Microscope in Ultrahigh Vacuum for Studying Electronic Properties of 2-Dimensional Materials

MRI：开发超高真空超快光致发光和瞬态吸收显微镜，用于研究二维材料的电子特性

• 批准号: 1826790
• 负责人: John Asbury
• 金额: $ 99.93万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-10-01 至 2023-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1826790&HistoricalAwards=false
• 关键词: MRI; Development; Ultrafast; Photoluminescence; Transient

The ability to control the growth and doping of semiconductors such as silicon enabled the development of electronic materials that revolutionized modern society in the digital age. Two-dimensional materials such as transition metal dichalcogenides are a new class of electronic materials that have the potential to open new technological advances on a similar scale. Major advances in the growth of two-dimensional materials have occurred in recent years. However, there remains a fundamental need to develop doping and processing chemistries that enable the control of the electronic properties of two-dimensional materials. The instrument developed in this project combines an ultrafast photoluminescence and transient absorption microscope, to characterize the electronic properties of two-dimensional materials, with an ultrahigh vacuum system that controls doping chemistries. It significantly expands the research infrastructure for users of the NSF Materials Innovation Platform focused on two-dimensional materials by enabling correlative measurements at the same locations in the samples using multiple characterization methods. The instrument serves a user-base of researchers both at Pennsylvania State University and in the broader national two-dimensional materials community. Graduate students and post-doctoral scholars using the instrument gain important professional development experience by facilitating workshops and associated training modules that are offered and advertised through the Materials Research Institute at Pennsylvania State University and the Center for Atomically Thin Multifunctional Coatings, which is an Industry-University Cooperative Research Center. The development of the ultrafast photoluminescence and transient absorption microscope in an ultrahigh vacuum system opens the ability to probe both emissive and non-emissive states with ultrafast time resolution in an imaging platform. It also enables the control of the sample environment and doping chemistry for characterization of the electronic and transport properties of two-dimensional materials. These capabilities are critical because two-dimensional materials are single- or few layer-structures with electronic properties that are strongly influenced by surface interactions. Furthermore, many of the electronic states involved in charge transfer and transport in two-dimensional materials are weakly- or non-emissive with diffusion properties and lifetimes that depend sensitively on the epitaxial alignment and growth of the materials. The ultrafast microscopy capability of the instrument combined with an ultrahigh vacuum sample transfer system and attached preparation chamber enables the dynamics and transport of excitons and charge carriers to be spatially and temporally resolved and correlated with their growth and doping chemistries. The electronic and transport properties of the same regions of the samples can be investigated using scanned probe and electron microscopy measurements and photoemission studies for complete characterization and development of design rules that will guide the development of two-dimensional materials and devices.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.

控制半导体（例如硅）的增长和掺杂的能力，可以开发在数字时代彻底改变现代社会的电子材料。二维材料（例如过渡金属二甲藻类）是一类新的电子材料，具有类似规模的新技术进步的潜力。近年来，二维材料增长的重大进展。但是，仍有基本需要开发兴奋剂和加工化学，以控制二维材料的电子性质。该项目中开发的仪器结合了超快的光致发光和瞬态吸收显微镜，以表征二维材料的电子性能，以及控制掺杂化学物质的超高真空系统。它可以通过使用多种表征方法在样本中的相同位置启用相关测量，从而为NSF材料创新平台的用户大大扩展了研究基础架构。该乐器在宾夕法尼亚州立大学和更广泛的国家二维材料社区中为研究人员提供了用户基础。使用该工具的研究生和博士后学者，通过促进研讨会和相关的培训模块，通过宾夕法尼亚州立大学的材料研究所和原子上稀薄的多功能涂料中心提供和宣传相关的培训模块，从而获得了重要的专业发展经验。超高真空系统中超快光致发光和瞬态吸收显微镜的发展开辟了能够在成像平台中使用超快时间分辨率探测发射和非发射状态的能力。它还可以控制样品环境和兴奋剂化学，以表征二维材料的电子和传输性能。这些功能至关重要，因为二维材料是具有电子特性的单层或几个层结构，它们受表面相互作用的强烈影响。此外，在二维材料中涉及电荷转移和运输的许多电子状态都是弱或不隔离的，具有扩散性能和寿命，这些特性依赖于材料的外延比对和生长。仪器的超快显微镜能力与超高真空样品转移系统结合使用，并连接的制备室使激子的动力和载体的动力和运输能够在空间和时间上解决，并与它们的生长和兴奋剂化学作用。可以使用扫描的探针和电子显微镜测量和光发射研究来研究样品相同区域的电子和传输特性，以完成设计规则的完整表征和制定，这些规则将指导二维材料和设备的开发。该奖项反映了NSF的法定任务，并通过使用基金会的Merit进行了评估，并通过评估了CRCRITAIL和BRODITAIL和BRODITIAL和BRODITAIL和BRODITAIL和BRODITAIL和BRODITAIL和BRODITIAL和BRODITIAL和BRODITAIL和BRODITAILATIAL和BRODITIAL和BRODITIAL和BRODITAILAILATIAS。