调节 p-Si(111) 光伏通过分子半导体电子合
Dylan G Boucher1, Kara Kearney2, Elif Ertekin2,3
1Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States.
Journal of the American Chemical Society
|February 3, 2021
概括
用分子对半导体表面进行化学修改, 精确控制频段对齐, 提高太阳能燃料设备的性能. 这项研究揭示了分子结构如何影响优化光电化学应用的电子合和界面二极管.
科学领域:
- 材料科学
- 表面化学
- 电化学
背景情况:
- 光电化学 (PEC) 装置的效率基本上受半导体连接能量和频段对齐限制.
- 通过分子功能化控制这些特性为改善太阳能燃料发电提供了一个有前途的策略.
研究的目的:
- 研究化学功能化p型 (pSi) 表面及其光电化学性能之间的结构功能关系.
- 阐明分子修饰半导体连接处的化学结构,电子合和界面二极体的相互作用.
主要方法:
- 各种烯表面修饰剂 (,,,) 的共价附着在pSi(111) 表面上.
- 使用甲基生物素作为氧化还原媒介的电化学表征,以确定带边移位和屏障高度.
- 光电化学测量以评估太阳能燃料的性能 (Voc).
- 用密度功能理论 (DFT) 计算来分析功能化接口的电子结构.
主要成果:
- 实现了具有低缺陷密度 (< 50 cm/s) 的高保真 pSi{111) 表面.
- 观察到带边的系统变化 (高达0.99V的屏障高度) 和高光电化学性能 (Voc高达0.43V与MV2+),与界面二极管相关.
- 功能化扩展到演变反应 (HER) 条件,在pSi111-RRRTiO2的Pt架构中显示可调节的Voc.
- DFT计算显示了基于分子的电子状态和带边缘之间的混合,表明电子合和界面状态诱导密度 (IDIS) 的形成.
结论:
- 分子功能化为PEC设备提供精确的半导体能量和频段对齐控制.
- 表面修饰器的化学结构决定了界面双极形成和电子合,显著影响了性能.
- 这些发现突显了接口化学,电子结构和设备效率之间的关键相互作用,为先进的太阳能燃料系统的合理设计铺平了道路.
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