Department of Applied Physics and Materials Research Center, The Hong Kong Polytechnic University , Hong Kong, China.
ACS Appl Mater Interfaces. 2013 Dec 26;5(24):13022-8. doi: 10.1021/am4039213. Epub 2013 Dec 13.
Herein we present a theoretical analysis on the optical properties and the photocurrent enhancement of nanotube-based dye-sensitized solar cells (DSSCs) coupled with a TiO2 nanotube (NT) photonic crystal (PC). It is found that the introduction of a TiO2 nanotube PC produces both Bragg mirror effect and Fabry-Perot cavity behavior, leading to a significant enhancement of light harvesting for photons in the photonic bandgap and at the two band edges. In addition, an increased amount of surface-anchored dye due to the larger surface area in the NT PC layer also causes absorption enhancement in the whole visible spectrum. The effects of structural parameters of the PC, such as the thickness of the PC layer, the axial lattice constant, the diameter of the nanotube, and light incident angle, on the optical properties and photocurrent magnification are thoroughly studied. The optimum structural parameters are proposed, which not only provide guidance but also offer further opportunities in the design and applications of TiO2 nanotube photonic crystals.
本文对基于纳米管的染料敏化太阳能电池（DSSC）与 TiO2 纳米管（NT）光子晶体（PC）结合后的光学性质和光电流增强进行了理论分析。结果表明，TiO2 纳米管 PC 的引入产生了布拉格反射镜效应和法布里-珀罗腔行为，从而显著增强了光子在光子带隙和两个带边缘的光捕获。此外，由于 NT PC 层的更大表面积，表面固定染料的数量增加，也导致整个可见光谱的吸收增强。深入研究了 PC 的结构参数（如 PC 层的厚度、轴向晶格常数、纳米管的直径和光入射角）对光学性质和光电流放大的影响。提出了最佳的结构参数，不仅提供了指导，而且为 TiO2 纳米管光子晶体的设计和应用提供了进一步的机会。
