Digdaya Ibadillah A, Trześniewski Bartek J, Adhyaksa Gede W P, Garnett Erik C, Smith Wilson A
Materials for Energy Conversion and Storage (MECS), Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands.
Center for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands.
J Phys Chem C Nanomater Interfaces. 2018 Mar 15;122(10):5462-5471. doi: 10.1021/acs.jpcc.7b11747. Epub 2018 Feb 7.
Metal-insulator-semiconductor (MIS) photoelectrodes offer a simple alternative to the traditional semiconductor-liquid junction and the conventional p-n junction electrode. Highly efficient MIS photoanodes require interfacial surface passivating oxides and high workfunction metals to produce a high photovoltage. Herein, we investigate and analyze the effect of interfacial oxides and metal workfunctions on the barrier height and the photovoltage of a c-Si photoanode. We use two metal components in a bimetal contact configuration and observe the modulation of the effective barrier height and the resulting photovoltage as a function of the secondary outer metal. The photovoltage shows a strong linear dependence by increasing the inner metal workfunction, with the highest photovoltage achieved by a MIS photoanode using a platinum inner metal. We also found that coupling a thin aluminium oxide with an interfacial silicon oxide and controlling the oxide thickness can significantly improve the photovoltage of an MIS junction photoanode.
金属-绝缘体-半导体（MIS）光电极提供了一种替代传统半导体-液体结和传统p-n结电极的简单方案。高效的MIS光阳极需要界面表面钝化氧化物和高功函数金属来产生高光电电压。在此，我们研究并分析了界面氧化物和金属功函数对c-Si光阳极的势垒高度和光电电压的影响。我们在双金属接触配置中使用两种金属成分，并观察有效势垒高度的调制以及由此产生的光电电压作为二次外层金属的函数。通过增加内层金属功函数，光电电压呈现出强烈的线性依赖性，使用铂作为内层金属的MIS光阳极实现了最高的光电电压。我们还发现，将薄氧化铝与界面氧化硅耦合并控制氧化物厚度可以显著提高MIS结光阳极的光电电压。
