Department of Materials Science and Engineering, Yonsei University , 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
Advanced Materials Division, Korea Research Institute of Chemical Technology (KRICT) , 141 Kajeong-ro, Yuseong, Daejeon 305-600, Republic of Korea.
ACS Appl Mater Interfaces. 2017 Apr 26;9(16):14078-14087. doi: 10.1021/acsami.7b01208. Epub 2017 Apr 13.
Efficient sunlight-driven water-splitting devices can be achieved by using an optically and energetically well-matched pair of photoelectrodes in a tandem configuration. The key for maximizing the photoelectrochemical efficiency is the use of a highly transparent front photoelectrode with a band gap below 2.0 eV. Herein, we propose two-dimensional (2D) photonic crystal (PC) structures consisting of a CuFeO-decorated microsphere monolayer, which serve as self-light-harvesting architectures allowing for amplified light absorption and high transparency. The photocurrent densities are evaluated for three CuFeO 2D PC-based photoelectrodes with microspheres of different sizes. The optical analysis confirmed the presence of a photonic stop band that generates slow light and at the same time amplifies the absorption of light. The 410 nm sized CuFeO-decorated microsphere 2D PC photocathode shows an exceptionally high visible light transmittance of 76.4% and a relatively high photocurrent of 0.2 mA cm at 0.6 V vs a reversible hydrogen electrode. The effect of the microsphere size on the carrier collection efficiency was analyzed by in situ conductive atomic force microscopy observation under illumination. Our novel synthetic method to produce self-light-harvesting nanostructures provides a promising approach for the effective use of solar energy by highly transparent photocathodes.
高效的太阳光驱动水分解装置可以通过在串联配置中使用光学和能量上匹配良好的一对光电管来实现。最大限度地提高光电化学效率的关键是使用带隙低于 2.0eV 的高度透明的前光电管。在此，我们提出了由 CuFeO 修饰的微球单层组成的二维（2D）光子晶体（PC）结构，它们作为自采集光结构，允许放大光吸收和高透明度。评估了三种具有不同尺寸微球的基于 CuFeO 2D PC 的光电管的光电流密度。光学分析证实存在光子带隙，可产生慢光并同时放大光的吸收。410nm 尺寸的 CuFeO 修饰微球 2D PC 光阴极显示出异常高的可见光透过率为 76.4%，在相对于可逆氢电极 0.6V 的光下，光电流为 0.2mA cm。在光照下通过原位导电原子力显微镜观察分析了微球尺寸对载流子收集效率的影响。我们生产自采集光纳米结构的新型合成方法为高效透明光阴极有效利用太阳能提供了一种有前途的方法。
