CAREER: Novel Electrodeposition Method using Water-In-Salt Electrolytes for Superconductor Thin Film Fabrication

这项学院早期职业发展(Career)补助金将研究新发现的“盐中之水”电解质，这将有可能使制造应用于量子设备的超导体成为可能。超导体是一种独特的材料，它允许电流在没有任何阻力的情况下流动，从而在能源效率和计算应用方面提供了巨大的进步。低温量子计算机和其他低温电子设备需要超导线路，以避免电阻加热，这会增加温度并扰乱这些设备的性能。传统集成电路中的布线是使用电沉积工艺制造的，但这种工艺不适用于超导体。由传统电解液电沉积的薄膜缺乏结构精度，当薄膜进一步加工成完整的电路时，超导电性会降低。该项目将重点开发一种新的“盐中之水”电解液，有望改善薄膜结构。这项工作将提供对沉积化学和过程的基本了解，以及这些因素如何影响薄膜的形貌和超导电性。其目标是使这种电沉积过程能够用于超导电路的工业制造。将建立和加强与当地儿童博物馆和当地高中的合作，以提高K-12学生和家长，特别是代表人数不足的群体对科学和工程教育和职业的认识。此外，研究成果还将有助于开发本科生/研究生课程的新课程模块：“电化学工程与微制造”。盐中水可以被视为一种没有游离水的水溶液电解质，因为超高浓度盐的水合作用会耗尽水分子。这是由于离子周围形成了水鞘，导致质子和水的还原受到很大的抑制。该项目利用这种盐中水电解液来实现用于制备超导薄膜的新的电沉积工艺，旨在提供对以下方面的基本了解：i)溶质的形态和浓度如何影响氢和其他杂质元素的掺入和分布；ii)电沉积过程(如电压偏置、脉冲宽度和流体力学)如何影响成核和生长、薄膜应力和颗粒结构；iii)衬底、应力层、盖层和热退火工艺如何改变颗粒结构、杂质分布、放气、薄膜应力和超导电性。该项目还旨在将这些知识与电解液一起整合到沉积工艺的设计中，以实现超导电路的制造。该项目将允许首席研究人员推进在电化学工程、材料科学、超导和电子器件方面的知识基础，并建立他在先进制造方面的长期职业生涯。该奖项反映了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。

This Faculty Early Career Development (CAREER) grant will investigate the newly discovered “water-in-salt” electrolytes, which will potentially enable the fabrication of superconductors for applications in quantum devices. A superconductor is a unique material that allows an electrical current to flow without experiencing any resistance, providing for tremendous advances in energy efficiency and computing applications. Low temperature quantum computers and other cryogenic electronic devices require superconducting wirings to avoid resistive heating, which increases the temperature and perturbs the performance of those devices. The wiring in conventional integrated circuits has been manufactured using electrodeposition processes, but such a process is not available for superconductors. Films electrodeposited from conventional electrolytes lack structural precision, and the superconductivity degrades when the films are further processed into complete circuits. This project will focus on the development of a new “water-in-salt” electrolyte that is expected to improve the film structures. This work will provide a fundamental understanding of the deposition chemistry and the process, as well as how these factors impact the morphology and superconductivity of the films. The goal is to enable such electrodeposition processes for the industrial manufacturing of superconducting circuits. Collaborations with a local children’s museum and local high schools will be established and strengthened, in order to promote the awareness of science and engineering education and careers among K-12 students and parents, particularly from underrepresented groups. In addition, the research results will contribute to the development of new class modules for the undergraduate/graduate-level course: “Electrochemical Engineering and Microfabrication.”Water-in-salt can be viewed as an aqueous electrolyte without free water, as the hydration of a super high concentration of salt depletes the water molecules. This is due to the formation of sheaths of water around the ions, resulting in a much suppressed reduction of protons and water. This project takes advantage of such water-in-salt electrolytes to enable new electrodeposition processes for superconducting film fabrication, aiming to provide fundamental understandings of: i) how the speciation and concentration of solutes impact the incorporation and distribution of hydrogen and other impurity elements; ii) how electrodeposition processes such as voltage bias, pulse duration, and hydrodynamics influence the nucleation and growth, film stress, and grain structure; and iii) how the substrates, stress layers, capping layers, and thermal annealing processes may change the grain structure, impurity distribution, outgassing, film stress, and superconductivity. This project also aims to integrate this knowledge into the design of deposition processes, in conjunction with the electrolyte, to enable superconductor circuit manufacturing. This project will allow the Principal Investigator to advance the knowledge base in Electrochemical Engineering, Material Sciences, Superconducting and Electronic Devices, and establish his long-term career in advanced manufacturing.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.