SuSChEM: Engineering Local Conductivity in MIS Photoelectrodes for Solar-Powered Water Splitting

太阳能从水中生产氢气提供了潜在的可能性，使太阳能能够以化学燃料的形式储存，这种电能是暂时可用的。这种能力将允许能量被暂时储存，然后在需求较高但阳光相对较低的时候进行部署。此外，将太阳能转换为氢燃料将有助于为采用燃料电池汽车的氢基交通基础设施奠定基础。高效、成本效益高的太阳能从水中生产氢气仍然是一项科学和技术挑战。该项目将研究半导体电子领域的概念，以使新的方法能够制造高效、低成本的光电电极，利用阳光中的能量将水分子分解为氢和氧。具体地说，光电极将被设计成厚的氧化层，作为与设备的液态水界面的保护层。在光电极中规模较小的情况下，局部导电区将被设计为使电子能够在吸收阳光的半导体区域和帮助将水分子分解为氢和氧的水溶液之间轻松移动。在教育影响方面，该项目将在电气工程专业一年级学生的入门课程中引入新的组件。这些组件将为学生提供设计和创建各种工程系统的物理原型所需的专业知识。通过在大学学术生涯之初发展这些能力，学生们将能够在接下来的教育中广泛应用这些能力。这个项目将寻求设计跨越绝缘氧化层的局部导电路径，用于高效和稳定的硅基金属-绝缘体-半导体(MIS)光电极，用于太阳能驱动的水分解。这些研究将建立在通过管理信息系统设备中的电击穿来实现局部导电性工程方面的最新进展，这些设备已经实现了高度稳定的硅基管理信息系统光电阴极和光阳极。主要的三个基础研究方向是：(I)研究吸收体和催化剂之间的局域传导路径对光电流密度、光电压和其他信息管理系统光电极性能的影响；(Ii)设计一种基于薄膜金属化反应的新的、可扩展的方法，用于设计和优化用于水分解的管理信息系统光电极保护氧化层的局部电导；(Iii)利用扫描电化学显微镜表征水分解活性的空间不均匀性及其与材料和器件制造工艺的关系。跨越材料加工、电化学和固态器件物理等学科的交叉培养，可以增加与硅基电子和光伏相关的技术基础设施对太阳能燃料发电和相关储能能力的影响。

Solar-powered production of hydrogen from water offers the potential to enable solar power, which is available on a transient basis, to be stored in the form of a chemical fuel. This capability would allow the energy to be stored temporarily, then deployed during times of high demand but relatively low availability of sunlight. In addition, conversion of solar energy into hydrogen fuel would help provide the foundation for a hydrogen-based transportation infrastructure incorporating fuel-cell vehicles. Efficient and cost-effective solar-powered production of hydrogen from water remains a scientific and technological challenge. This project will investigate concepts from the field of semiconductor electronics to enable new approaches to make efficient, low-cost photoelectrodes for splitting water molecules into hydrogen and oxygen using the energy in sunlight. Specifically, photoelectrodes will be designed with thick oxide layers that serve as a protective coating at the liquid water interface with the device. At a smaller scale in the photoelectrode, local regions that are electrically conductive will be designed to enable electrons to move easily between the semiconductor region where sunlight is absorbed and the aqueous solution in which the electrons help split water molecules into hydrogen and oxygen. For educational impacts, the project will introduce new components into an introductory-level course for freshman students in electrical engineering. These components will provide students with expertise required to design and to create physical prototypes of a wide range of engineered systems. By developing these capabilities at the outset of their university academic careers, students will be able to deploy them extensively throughout the remainder of their education.This project will seek to engineer localized electrical conduction paths across insulating oxide layers for efficient and stable Si-based metal-insulator-semiconductor (MIS) photoelectrodes for solar-driven water splitting. These investigations will build upon recent advances in the engineering of local conductivity via electrical breakdown in MIS devices that have enabled highly stable, Si-based MIS photocathodes and photoanodes. Three primary fundamental research directions will be pursued: (i) investigation of the influence of localized conduction paths between absorber and catalyst on photocurrent density, photovoltage and other aspects of MIS photoelectrode performance; (ii) engineering of a new, scalable approach, based on thin-film metallization reactions, for engineering and optimizing local conductivity across protective oxide layers for MIS photoelectrodes for water splitting; and (iii) characterization of spatial inhomogeneity in water splitting activity, and its relationship with material and device fabrication processes, using scanning electrochemical microscopy. Cross-fertilization spanning the disciplines of materials processing, electrochemistry, and solid-state device physics could enable increased impact of the technological infrastructure associated with silicon-based electronics and photovoltaics on solar fuel generation and the associated energy storage capability.