Chen Wei, Luo Shiqiang, Wan Zunyuan, Feng Xiyuan, Liu Xinke, He Zhubing
Opt Express. 2017 Apr 17;25(8):A253-A263. doi: 10.1364/OE.25.00A253.
As it already made huge effect in the commercialization of silicon and other photovoltaics, interface engineering is dispensable in the current and future evolution of hybrid perovskite solar cells (PSCs) techniques. In order to solve carriers' recombination and detention at the cathode side of planar PSCs, in this work, Ruthenium acetylacetonate (RuAcac) was successfully adopted as a reliable and stable cathode interfacial layer (CIL) to improve the inverted planar PSCs. The power conversion efficiency of the optimal devices was enhanced from 12.74% for the control device without RuAcac, to 17.15% for the RuAcac based devices, with an open circuit voltage of 1.077 V, a short circuit current density of 21.28 mA/cm, and fill factor of 74.7% correspondingly. A series of photon-physics and microscopy protocols, including EQE, UPS, XPS, PL and SKPM, were used to discover the function of RuAcac CIL. Those results confirms an identical conclusion that RuAcac enables the formation of quasi-ohmic contact at the cathode side by eliminating the energy level barrier between the LUMO of PCBM and Fermi level of silver electrode. The low temperature and facile processed Ruthenium acetylacetonate in this work definitely offer us a robust interface-engineering way for the perovskite solar cells and also their commercialization.
由于界面工程在硅和其他光伏材料的商业化中已经产生了巨大影响，因此在混合钙钛矿太阳能电池（PSC）技术的当前和未来发展中，界面工程是不可或缺的。为了解决平面PSC阴极侧载流子的复合和滞留问题，在这项工作中，成功采用乙酰丙酮钌（RuAcac）作为可靠且稳定的阴极界面层（CIL）来改进倒置平面PSC。最优器件的功率转换效率从不含RuAcac的对照器件的12.74%提高到基于RuAcac的器件的17.15%，相应的开路电压为1.077 V，短路电流密度为21.28 mA/cm²，填充因子为74.7%。一系列光子物理和显微镜方法，包括EQE、UPS、XPS、PL和SKPM，被用于探究RuAcac CIL的功能。这些结果证实了一个相同的结论，即RuAcac通过消除PCBM的最低未占分子轨道（LUMO）与银电极费米能级之间的能级势垒，在阴极侧形成了准欧姆接触。这项工作中低温且易于加工的乙酰丙酮钌无疑为钙钛矿太阳能电池及其商业化提供了一种强大的界面工程方法。
