High performance solar photoelectrodes based on thin-film reactions

这个项目旨在开发新的设备，利用太阳能进行必要的化学反应，将水转化为氢和氧。这种应用的传统设备，被称为光电极，在工作效率和寿命之间存在基本的权衡，因为有效吸收阳光的材料通常在所需的工作条件下会降解。此外，到目前为止，制造成本加上有限的性能，使得用这种装置从太阳能中生产氢不经济。基于晶体硅（绝大多数商用太阳能电池中使用的相同材料）的高度可扩展，低成本的材料加工方法已经显示出生产高性能，低成本光电极的希望。该项目将推进利用此类材料从太阳能中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。与此同时，研究小组将开发项目和材料，使小学生和中学生能够了解可再生能源和光的基本性质，这是现代社会中对公民越来越重要的话题，使用廉价的日常用品制成的低成本可见光光谱仪，连接在智能手机相机上。该项目旨在设计和开发用于太阳能驱动水分解的金属-绝缘体-半导体（MIS）光电阳极和光电阴极，这些光电阳极和光电阴极具有高性能、出色的稳定性和低成本的可扩展性。关键工作将包括实现改进的析氧反应催化剂（OER），利用可扩展、低成本、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，以及将这种方法初步应用于包含III-V半导体的MIS结构。本文将阐述用于太阳能驱动水分解的MIS光阳极和光电阴极的设计、制造、操作和性能等基本问题。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性质将在与半导体微电子和纳米电子学的传统应用非常不同的背景下进行探索。研究人员将开发新的方法来制造局部纳米级催化剂结构，并将其与厚保护性氧化物和底层半导体集成在一起。将探讨半导体内埋藏结的设计和结构、光生成的少数载流子的传输、催化剂岛的空间分布和通过保护性氧化层的导电路径之间的相互作用。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识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.