Plasmonic ZnO/Ag Embedded Structures as Collecting Layers for Photogenerating Electrons in Solar Hydrogen Generation Photoelectrodes |
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Authors: | Hao Ming Chen Chih Kai Chen Ming Lun Tseng Pin Chieh Wu Chia Min Chang Liang‐Chien Cheng Hsin Wei Huang Ting Shan Chan Ding‐Wei Huang Ru‐Shi Liu Din Ping Tsai |
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Affiliation: | 1. Department of Chemistry, National Taiwan University, Taipei, Taiwan 106;2. Department of Physics, National Taiwan University, Taipei, Taiwan 106;3. Graduate Institute of Applied Physics, National Taiwan University, Taipei, Taiwan 106;4. Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan 106;5. National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan;6. Department of Physics & Graduate Institute of Applied Physics, National Taiwan University, Taipei, Taiwan 106;7. Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan115 |
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Abstract: | A new fabrication strategy in which Ag plasmonics are embedded in the interface between ZnO nanorods and a conducting substrate is experimentally demonstrated using a femtosecond‐laser (fs‐laser)‐induced plasmonic ZnO/Ag photoelectrodes. This fs‐laser fabrication technique can be applied to generate patternable plasmonic nanostructures for improving their effectiveness in hydrogen generation. Plasmonic ZnO/Ag nanostructure photoelectrodes show an increase in the photocurrent of a ZnO nanorod photoelectrodes by higher than 85% at 0.5 V. Both localized surface plasmon resonance in metal nanoparticles and plasmon polaritons propagating at the metal/semiconductor interface are available for improving the capture of sunlight and collecting charge carriers. Furthermore, in‐situ X‐ray absorption spectroscopy is performed to monitor the plasmonic‐generating electromagnetic field upon the interface between ZnO/Ag nanostructures. This can reveal induced vacancies on the conduction band of ZnO, which allow effective separation of charge carriers and improves the efficiency of hydrogen generation. Plasmon‐induced effects enhance the photoresponse simultaneously, by improving optical absorbance and facilitating the separation of charge carriers. |
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Keywords: | hydrogen generation ZnO Ag plasmonics femtosecond‐laser direct‐write silver oxide |
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