超光子催化：非晶硅超表面编码光化学活性
Metaphotonic Catalysis: Amorphous silicon metasurfaces encode photochemical activity
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中文总结 AI 辅助
该研究提出全介质非晶硅超表面光电极，其可调控光化学活性分布，实现高效稳定的太阳能转燃料转化，析氢增强最高达21倍，为共振编程光催化提供了新平台。
中文摘要 AI 辅助
太阳能转燃料的转化可得益于具有定制光-物质相互作用的光电极，但大多数纳米结构设计对光化学活性的空间和光谱分布控制有限。本文提出一种全介质非晶硅超表面光电极，其将共振光-物质相互作用限制在220 nm厚的活性层内。可调谐的米氏型和导模共振可对化学反应性进行光谱编码，在硅带边附近产生超过80%的吸收率，而同厚度未图案化薄膜的吸收率低于30%。该超表面同时充当光吸收体、载流子传输层和催化界面，无需额外助催化剂或工程化钝化层。原位光扫描电化学显微镜显示其具有波长和结构依赖的氧化还原活性，且在硅带边附近的内部量子效率相对于平面薄膜提升了10倍。功率依赖测量证实该增强源于光子驱动而非非线性光热效应，表面敏感的超快瞬态反射测量则探究了潜在的载流子动力学。光耦合扫描电化学池显微镜进一步表明，在光催化条件下析氢增强可达21倍，在光电化学偏压下增强可达15倍，考虑到估计的表面积增加后，对应增强分别为11.2倍和7.7倍。该超表面在超过10小时的浸泡和持续激光照射下保持稳定。这些结果确立了非晶硅作为稳定且通用的平台，用于共振编程的光催化和太阳能燃料生成。
英文摘要
Solar-to-fuel conversion can benefit from photoelectrodes with engineered light-matter interactions, yet most nanostructured designs provide limited control over the spatial and spectral distribution of photochemical activity. Here, we present an all-dielectric amorphous-silicon metasurface photoelectrode that confines resonant light-matter interactions within a 220-nm-thick active layer. Tunable Mie-type and guided-mode resonances spectrally encode chemical reactivity and produce absorptance above 80% near the silicon band edge, compared with less than 30% for an unpatterned film of the same thickness. The metasurface simultaneously functions as the light absorber, carrier-transport layer, and catalytic interface without an added co-catalyst or engineered passivation layer. Operando photo-scanning electrochemical microscopy reveals wavelength- and structure-dependent redox activity and a tenfold enhancement in internal quantum efficiency near the silicon band edge relative to planar films. Power-dependent measurements support a photon-driven rather than nonlinear photothermal origin of the enhancement, while surface-sensitive ultrafast transient-reflectivity measurements probe the underlying carrier dynamics. Light-coupled scanning electrochemical cell microscopy further shows hydrogen-evolution enhancements of up to 21-fold under photocatalytic conditions and 15-fold under photoelectrochemical bias, corresponding to 11.2-fold and 7.7-fold enhancements after accounting for the estimated surface-area increase. The metasurfaces remain stable during more than 10 hours of immersion and prolonged laser illumination. These results establish amorphous silicon as a stable and versatile platform for resonantly programmed photocatalysis and solar-fuel generation.
