Lenyk Bohdan, Schöps Volker, Boneberg Johannes, Kabdulov Mikhail, Huhn Thomas, Scheer Elke, Offenhäusser Andreas, Mayer Dirk
Institute of Biological Information Processing (IBI-3), Forschungszentrum Jülich, 52428 Jülich, Germany.
Department of Physics, University of Konstanz, 78457 Konstanz, Germany.
Nano Lett. 2020 Jul 8;20(7):5243-5250. doi: 10.1021/acs.nanolett.0c01569. Epub 2020 Jun 18.
Diarylethene molecules are discussed as possible optical switches, which can reversibly transition between completely conjugated (closed) and nonconjugated (open) forms with different electrical conductance and optical absorbance, by exposure to UV and visible light. However, in general the opening reaction exhibits much lower quantum yield than the closing process, hindering their usage in optoelectronic devices. To enhance the opening process, which is supported by visible light, we employ the plasmonic field enhancement of gold films perforated with nanoholes. We show that gold nanohole arrays reveal strong optical transmission in the visible range (∼60%) and pronounced enhancement of field intensities, resulting in around 50% faster switching kinetics of the molecular species in comparison with quartz substrates. The experimental UV-vis measurements are verified with finite-difference time-domain simulation that confirm the obtained results. Thus, we propose gold nanohole arrays as transparent and conductive plasmonic material that accelerates visible-light-triggered chemical reactions including molecular switching.
二芳基乙烯分子被作为可能的光开关进行讨论，通过暴露于紫外光和可见光下，它们可以在具有不同电导率和光吸收的完全共轭（闭合）和非共轭（开放）形式之间可逆地转变。然而，一般来说，开放反应的量子产率比闭合过程低得多，这阻碍了它们在光电器件中的应用。为了增强由可见光支持的开放过程，我们利用了纳米孔穿孔的金膜的等离子体场增强效应。我们表明，金纳米孔阵列在可见光范围内显示出很强的光透射率（约60%）和场强的显著增强，与石英衬底相比，分子物种的开关动力学加快了约50%。通过有限时域差分模拟验证了实验紫外可见测量结果，证实了所得结果。因此，我们提出金纳米孔阵列作为透明导电等离子体材料，可加速包括分子开关在内的可见光触发的化学反应。
