Vapor-Phase Epitaxy of Single-Domain Halide Perovskites for Quantum Applications

非技术概述：薄膜卤化物钙钛矿半导体已经成为许多电子应用和太阳能转换的改变游戏规则的材料。钙钛矿型半导体由富含稀土的元素组成，能够获得与传统半导体如Si和GaAs相媲美的高性能。然而，人们对如何生长薄膜单晶仍然知之甚少，这可能有助于实现这类材料的最大潜力。该项目由美国国家科学基金会材料研究部的固态和材料化学计划资助，扩展了卤化物钙钛矿单晶生长动力学的知识。研究人员研究了无机和混合卤化物钙钛矿的精确控制薄膜沉积。这项基础研究为实现下一代薄膜钙钛矿量子应用、设计多层膜、高速晶体管提供了可能，并指导了稳定、低成本的卤化物钙钛矿太阳能电池的开发。作为技术项目的补充，协调的外联和教育努力扩大了“可持续能源和太阳能叮当空间”讲习班，包括密歇根州立大学校园实践能源教育的“衍射魔术”的新模块。此外，研究人员还制定了一年一度的艺术竞赛，以提高人们对创新材料科学研究的认识。这项研究最终使美国更接近最高性能的卤化物钙钛矿电子产品和量子设备的广泛应用。技术概述：该项目由美国国家科学基金会材料研究部的固态和材料化学计划资助，旨在加深对自下而上合成顺序和性质可控的卤化物钙钛矿外延薄膜和超晶格的理解。与它们的氧化物类似物相比，卤化物钙钛矿体系界面上发生的突现现象的研究一直没有得到充分的探索和开发。因此，对晶体顺序、取向、应变和量子限制的控制是优化这些卤化物钙钛矿材料能量迁移的基础，这些材料用于下一代高性能光伏、光电子学和量子简并二维电子系统。利用气相生长，研究人员探索并发现了钙钛矿薄膜的异质外延生长模式，这种模式还可以使用针对绝缘和半导体衬底的生长进行优化的实时和原位衍射技术来制造量子受限多层膜。建立了定制外延薄膜和量子阱的晶相、化学计量比、应变和掺杂分布的路线，以实现高质量二维电子系统中的电子多体相，并确定结构和量子性质之间的联系，以指导未来的器件开发。作为技术项目的补充，协调的外联和教育努力扩大了“可持续能源和太阳能叮当空间”讲习班，包括密歇根州立大学校园实践能源教育的“衍射魔术”的新模块。此外，研究人员还制定了一年一度的艺术竞赛，以提高人们对创新材料科学研究的认识。这项研究最终使美国更接近最高性能的卤化物钙钛矿电子产品和量子设备的广泛应用。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Non-Technical Summary:Thin film halide perovskite semiconductors have emerged as game-changing materials for many electronic applications and for solar energy conversion. Perovskite semiconductors are composed of earth-abundant elements, and are capable of achieving high performance comparable to traditional semiconductors such as Si and GaAs. However, there is still very little understanding how to grow thin film single crystals that could help lead to the highest potential for this class of material. This project, funded by the Solid State and Materials Chemistry program in the Division of Materials Research at NSF, expands the knowledge of accessible single-crystal growth dynamics for halide perovskites. The researchers study precisely controlled thin-film deposition of inorganic and hybrid halide perovskites. This fundamental research enables the realization of next generation thin-film perovskite quantum applications, designer multilayers, high speed transistors, and guides the development of stable and low-cost halide perovskite solar cells. To complement the technical project, a coordinated outreach and educational effort expands "Sustainable- and Solar-Energy Tinker-Space" workshops to include new modules on "The Magic of Diffraction" for hands-on energy education on the Michigan State University campus. Additionally, the researchers develop an annual art competition to raise awareness of innovative Materials Science research. This research ultimately brings the U.S. closer to the widespread application of the highest performance halide perovskite electronics and quantum devices. Technical Summary:This project, funded by the Solid State and Materials Chemistry program in the Division of Materials Research at NSF, furthers the understanding of the bottom-up synthesis of halide perovskite epitaxial films and superlattices with controlled order and properties. Compared to their oxide analogues, the study of emergent phenomenon occurring at the interface for halide perovskite system has been underexplored and underexploited. Control over crystalline order, orientation, strain, and quantum confinement are therefore fundamental to the optimization of energy migration in these halide perovskite materials for the next generation high performance photovoltaics, optoelectronics and quantum degenerate two-dimensional electron systems. Employing vapor growth, the researchers explore and uncover heteroepitaxial growth modes of perovskite films that also enable the fabrication of quantum confined multilayers using real-time and in-situ diffraction techniques optimized for growth on both insulating and semiconducting substrates. Routes to tailoring the crystalline phase, stoichiometry, strain, and doping profiles of epitaxial films and quantum wells are established to realize electronic many-body phases in high-quality two-dimensional electron systems and determine the connection between structure and quantum properties that can guide future device development. To complement the technical project, a coordinated outreach and educational effort expands "Sustainable- and Solar-Energy Tinker-Space" workshops to include new modules on "The Magic of Diffraction" for hands-on energy education on the Michigan State University campus. Additionally, the researchers develop an annual art competition to raise awareness of innovative Materials Science research. This research ultimately brings the U.S. closer to the widespread application of the highest performance halide perovskite electronics and quantum 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.