Enhanced Incident Photon-to-Electron Conversion Efficiency of Tungsten Trioxide Photoanodes Based on 3D-Photonic Crystal Design
Enhanced Incident Photon-to-Electron Conversion Efficiency of Tungsten Trioxide Photoanodes Based on 3D-Photonic Crystal Design
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DOI：
10.1021/nn200100v
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发表时间：
2011-06-01
期刊：
影响因子：
17.1
通讯作者：
Zou, Zhigang
中科院分区：
文献类型：
--
作者：
Chen, Xiaoqing;Ye, Jinhua;Zou, Zhigang
在这项研究中，三维光子晶体设计被用来提高入射光子到电子转换效率（IPCE）的WO 3光阳极。制备了大面积、高质量的反蛋白石结构WO 3光子晶体光阳极。这些WO 3光阳极的光子阻带的实验调谐通过改变反蛋白石结构的孔径。结果表明，当WO 3反蛋白石的光子阻带红边与WO 3的电子吸收边在E-9 = 2.6- 2.8eV处重叠时，在可见光照射下（λ> 400 nm），与无序多孔WO 3光阳极相比，光电流强度最大增加100%.当阻带的红边在WO 3的电子吸收范围内调谐良好时，观察到明显但幅度较小的光电流强度增强。结果表明，在非垂直入射条件下，WO 3反蛋白石的选择性IPCE增强光谱区的波长发生蓝移，这与计算得到的阻带边缘位置一致。这种增强可以归因于由于光子阻带边缘的慢光效应而导致的更长的光子物质相互作用长度，从而导致光捕获效率的显着提高。该方法为可见光响应光阳极中有效利用太阳能提供了一种潜在的、有前途的方法。
In this study, 3D-photonic crystal design was utilized to enhance incident photon-to-electron conversion efficiency (IPCE) of WO3 photoanodes. Large-area and high-quality WO3 photonic crystal photoanodes with Inverse opal structure were prepared. The photonic stop-bands of these WO3 photoanodes were tuned experimentally by variation of the pore size of inverse opal structures. It was found that when the red-edge of the photonic stop-band of WO3 inverse opals overlapped with the WO3 electronic absorption edge at E-9 = 2.6-2.8 eV, a maximum of 100% increase in photocurrent intensity war observed under visible light irradiation (lambda > 400 nm) in comparison with a disordered porous WO3 photoanode. When the red-edge of the stop-band was tuned well within the electronic absorption range of WO3, noticeable but less amplitude of enhancement In the photocurrent intensity was observed. It was further shown that the spectral region with a selective IPCE enhancement of the WO3 Inverse opals exhibited a blue-shift in wavelength under off-normal Incidence of light, In agreement with the calculated stop-band edge locations. The enhancement could be attributed to a longer photon matter interaction length as a result of the slow-light effect at the photonic stop-band edge, thus leading to a remarkable improvement in the light-harvesting efficiency. The present method can provide a potential and promising approach to effectively utilize solar energy in visible-light-responsive photoanodes.