Indium Tin Oxide Photonic Crystal for Controllable Light Coupling in Solar Cells by an Inexpensive Soft Lithography with HD-DVD and Blu-ray

摘要

We present an indium tin oxide/polymethylsilsesquioxane (ITO/PMSSQ) photonic crystal (PC) with grating structure. This topography exhibits multiple coupling resonances in specific regions of the solar spectrum, which can be controlled by tuning the angle and polarization of incident light as demonstrated through simulation and experimental results. The ITO/PMSSQ grating structures are prepared by simple soft lithography procedures using commercial HD-DVD and Blu-ray as template molds. The surface topography also includes geometrical singularities such as nanogaps and nanocones, which lead to further enhanced light trapping characteristics. Together, these singularity-embedded photonic crystal gratings result in concentrated electromagnetic fields at the aforementioned singularities, which could be especially helpful in separating the tightly bonded excitons in organic solar cells. Simulation shows an absorption enhancement over the full spectral range of ITO PCs-based solar cells with substantial increases closer to the band edge under s-polarized light.