High performance solar photoelectrodes based on thin-film reactions

该项目旨在开发新的设备，利用太阳能进行必要的化学反应，将水转化为氢气和氧气。用于该应用的传统装置（称为光电极）在操作中遭受效率和寿命之间的根本权衡，因为有效吸收阳光的材料通常在所需的操作条件下降解。此外，迄今为止，制造成本与有限的性能相结合使得利用这种装置从太阳能生产氢不经济。一种基于晶体硅（与大多数商业太阳能电池中使用的材料相同）的高度可扩展、低成本的材料加工方法已显示出生产高性能、低成本光电极的前景。该项目将推进利用此类材料从太阳能发电产生化学燃料的基础科学和工程，寻求降低“绿色”氢的成本，使其与化石燃料竞争。同时，研究小组将开发项目和材料，使中小学生能够了解可再生能源和光的基本属性，这些主题对我们现代社会的公民越来越重要，使用低成本的可见光光谱仪，该项目旨在设计和开发金属-绝缘体-半导体（MIS）光电阳极和光电阴极用于太阳能驱动的水分解，提供高性能，出色的稳定性，以及低成本的高度可扩展的可制造性。关键工作将包括实现改进的析氧反应（OER）催化剂，使用可扩展的，低成本的，可制造的方法和地球丰富的催化剂材料制造和探索MIS光电阴极结构，以及这种方法对MIS结构的初步适应，包括III-V半导体。有关的设计，制造，操作和性能的MIS光电阳极和光电阴极的太阳能驱动的水分解的基本问题将得到阐明。涉及金属化层，绝缘氧化物和底层半导体衬底的薄膜反应的材料科学和纳米级特性将在与半导体微电子和纳米电子学中的传统应用非常不同的背景下进行探索。将开发用于制造与厚保护氧化物和底层半导体集成的局部纳米级催化剂结构的新方法。该奖项将探讨半导体内的掩埋结设计和结构、光生少数载流子的传输、催化剂岛的空间分布以及通过保护氧化层的导电路径之间的相互作用。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project aims to develop new devices that use power from sunlight to perform chemical reactions necessary to convert water to hydrogen and oxygen. Traditional devices for this application, referred to as photoelectrodes, suffer from fundamental tradeoffs between efficiency and longevity in operation, because materials that absorb sunlight efficiently are generally degraded under the required operating conditions. Also, manufacturing costs combined with limited performance have, to date, rendered the production of hydrogen from solar power with such devices uneconomic. A highly scalable, low-cost materials processing approach based on crystalline silicon (the same material used in the very large majority of commercial solar cells) has shown promise to yield high-performance, low-cost photoelectrodes. This project will advance fundamental science and engineering of generating chemical fuels from solar power with such materials, seeking to reduce the cost of “green” hydrogen to make it competitive with fossil fuels. Concurrently, the research team will develop projects and materials that will enable elementary and secondary school students to learn about renewable energy and fundamental properties of light, topics of increasing importance for citizens in our modern society, using a low-cost visible-light optical spectrometer, made from inexpensive everyday items and attached to a smartphone camera.This project seeks to design and develop metal-insulator-semiconductor (MIS) photoanodes and photocathodes for solar-driven water splitting that offer high performance, outstanding stability, and highly scalable manufacturability at low cost. Key efforts will include realization of improved catalysts for the oxygen evolution reaction (OER), fabrication and exploration of MIS photocathode structures using scalable, low-cost, manufacturable approaches and earth-abundant catalyst materials, and an initial adaptation of this approach to MIS structures incorporating III-V semiconductors. Fundamental issues pertaining to the design, fabrication, operation, and properties of MIS photoanodes and photocathodes for solar-driven water-splitting will be elucidated. The materials science and nanoscale properties of thin-film reactions involving metallization layers, insulating oxides, and an underlying semiconductor substrate will be explored, in a context very different from their traditional application in semiconductor micro- and nanoelectronics. New approaches for fabrication of localized nanoscale catalyst structures integrated with thick protective oxides and an underlying semiconductor will be developed. The interplay among buried junction design and structure within the semiconductor, transport of photo-generated minority carriers, and spatial distribution of catalyst islands and conductive paths through a protective oxide layer will be explored.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.