Kiani Fatemeh, Bowman Alan R, Sabzehparvar Milad, Sundararaman Ravishankar, Tagliabue Giulia
Laboratory of Nanoscience for Energy Technologies (LNET), STI, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
Department of Materials Science & Engineering, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, New York 12180, United States.
Nano Lett. 2024 Dec 18;24(50):16008-16014. doi: 10.1021/acs.nanolett.4c04319. Epub 2024 Nov 1.
Exploring nonequilibrium hot carriers from plasmonic metal nanostructures is a dynamic field in optoelectronics, with applications including photochemical reactions for solar fuel generation. The hot carrier injection mechanism and the reaction rate are highly impacted by the metal/molecule interaction. However, determining the primary type of reaction and thus the injection mechanism of hot carriers has remained elusive. In this work, we reveal an electron injection mechanism deviating from a purely outer-sphere process for the reduction of ferricyanide redox molecule in a gold/p-type gallium nitride (Au/p-GaN) photocathode system. Combining our experimental approach with ab initio simulations, we discovered that an efficient inner-sphere transfer of low-energy electrons leads to an enhancement in the photocathode device performance in the interband regime. These findings provide important mechanistic insights, showing our methodology as a powerful tool for analyzing and engineering hot-carrier-driven processes in plasmonic photocatalytic systems and optoelectronic devices.
探索来自等离子体金属纳米结构的非平衡热载流子是光电子学中的一个活跃领域，其应用包括用于太阳能燃料生成的光化学反应。热载流子注入机制和反应速率受到金属/分子相互作用的高度影响。然而，确定主要反应类型以及热载流子的注入机制仍然难以捉摸。在这项工作中，我们揭示了一种电子注入机制，该机制偏离了纯外层球过程，用于在金/p型氮化镓（Au/p-GaN）光电阴极系统中还原铁氰化物氧化还原分子。将我们的实验方法与从头算模拟相结合，我们发现低能电子的有效内层球转移导致光带间区域的光电阴极器件性能增强。这些发现提供了重要的机理见解，表明我们的方法是分析和设计等离子体光催化系统和光电器件中热载流子驱动过程的有力工具。
