Three-dimensional semiconductor nanowire networks as model systems to study physical processes in nanostructured electrodes for light-driven water splitting

三维半导体纳米线网络作为模型系统研究光驱动水分解纳米结构电极的物理过程

• 批准号: 279251490
• 负责人: Dr. Maria Eugenia Toimil-Molares
• 金额: --
• 依托单位: GSI Helmholtzzentrum für Schwerionenforschung GmbH
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/279251490?language=en
• 关键词: Three; dimensional; semiconductor; nanowire; networks

The aim of the proposed project is the development and characterization of three dimensional Cu2O/TiO2 and Si/TiO2 core/shell nanowire networks as model systems for photo-electrochemical conversion of solar energy into hydrogen production. Exploiting the wide options of the applied ion-track technology allowing us to tailor length, diameter, and crystallinity of the wires in an independent manner, the study focuses on the question how the geometry and crystallinity of the nanowire system affects the relevant physical processes such as light absorption, electron-hole pair generation, carrier transport, chemical reactions at the surface, and chemical- and photo-corrosion.Our approach takes into account the following promising aspects:- Compared to thin film technology, nanowires of several tens of µm length are expected to provide high efficiency in light absorption. This advantage is combined with efficient collection of photo-generated carriers across the only tens of nanometers wide radial wire axis.- Freestanding three dimensional arrays of highly interconnected cylindrical nanowires provide mechanically stable test systems and provide large semiconductor/electrolyte interfaces.- The nanowire networks will be coated conformally by means of atomic layer deposition (ALD) with TiO2 layers of various thicknesses to investigate the influence of the shell on the photoelectrochemical efficiency and chemical and mechanical stability of the networks.- Cu2O and Si are selected as systems because their respective band gaps promise maximize water splitting efficiency in the visible light regime. Electrical and optical properties of both materials are different from each other and yet well known as bulk and thin film systems, providing a good basis to investigate the influence of size-effects and material on the nanostructure photoelectrochemical properties.

该项目的目的是开发和表征三维Cu 2 O/TiO 2和Si/TiO 2核/壳纳米线网络，作为太阳能光电化学转化制氢的模型系统。利用广泛的应用离子轨道技术的选择，使我们能够以独立的方式定制线的长度，直径和结晶度，研究重点是纳米线系统的几何形状和结晶度如何影响相关的物理过程，如光吸收，电子空穴对产生，载流子传输，表面化学反应，我们的方法考虑了以下有前途的方面：-与薄膜技术相比，几十微米长的纳米线有望提供高效率的光吸收。这一优势与光生载流子在仅几十纳米宽的径向线轴上的有效收集相结合。高度互连的圆柱形纳米线的独立三维阵列提供机械稳定的测试系统，并提供大的半导体/电解质界面。纳米线网络将通过原子层沉积（ALD）用各种厚度的TiO 2层保形地涂覆，以研究壳对网络的光电化学效率以及化学和机械稳定性的影响。选择Cu 2 O和Si作为系统，因为它们各自的带隙保证在可见光范围内最大化水分解效率。这两种材料的电学和光学性质是彼此不同的，但众所周知的散装和薄膜系统，提供了一个很好的基础，研究尺寸效应和材料对纳米结构光电化学性能的影响。