Standing wave enhancement of red absorbance and photocurrent in dye-sensitized titanium dioxide photoelectrodes coupled to photonic crystals
Standing wave enhancement of red absorbance and photocurrent in dye-sensitized titanium dioxide photoelectrodes coupled to photonic crystals
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DOI：
10.1021/ja034650p
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发表时间：
2003-05-21
影响因子：
15
通讯作者：
Frank, AJ
中科院分区：
文献类型：
--
作者：
Nishimura, S;Abrams, N;Frank, AJ
通过将 TiO2 光子晶体层耦合到传统的 TiO2 纳米粒子薄膜，提高了染料敏化光电极的光捕获效率。除了充当介电镜之外，反蛋白石光子晶体还导致染料吸光度发生显着变化，这取决于阻带的位置。吸光度在短于阻带最大值的波长处被抑制，而在更长的波长处被增强。这种效应是由光在阻带附近的慢群速度以及随后光子晶体的空隙（蓝色）或染料敏化 TiO2（红色）部分中的光强度局部化引起的。通过将光子晶体与 TiO2 纳米粒子薄膜耦合，相对于普通染料敏化纳米晶 TiO2 光电极，可见光谱（400-750 nm）的短路光电流效率可提高约 26%。
The light harvesting efficiency of dye-sensitized photoelectrodes was enhanced by coupling a TiO2 photonic crystal layer to a conventional film of TiO2 nanoparticles. In addition to acting as a dielectric mirror, the inverse opal photonic crystal caused a significant change in dye absorbance which depended on the position of the stop band. Absorbance was suppressed at wavelengths shorter than the stop band maximum and was enhanced at longer wavelengths. This effect arises from the slow group velocity of light in the vicinity of the stop band, and the consequent localization of light intensity in the voids (to the blue) or in the dye-sensitized TiO2 (to the red) portions of the photonic crystal. By coupling a photonic crystal to a film of TiO2 nanoparticles, the short circuit photocurrent efficiency across the visible spectrum (400-750 nm) could be increased by about 26%, relative to an ordinary dye-sensitized nanocrystalline TiO2 photoelectrode.