Institute of Microelectronics, NCSR Demokritos, Terma Patriarchou Grigoriou, 15310 Aghia Paraskevi, Greece.
J Am Chem Soc. 2012 Oct 3;134(39):16178-87. doi: 10.1021/ja3026906. Epub 2012 Sep 21.
Molybdenum oxide is used as a low-resistance anode interfacial layer in applications such as organic light emitting diodes and organic photovoltaics. However, little is known about the correlation between its stoichiometry and electronic properties, such as work function and occupied gap states. In addition, despite the fact that the knowledge of the exact oxide stoichiometry is of paramount importance, few studies have appeared in the literature discussing how this stoichiometry can be controlled to permit the desirable modification of the oxide's electronic structure. This work aims to investigate the beneficial role of hydrogenation (the incorporation of hydrogen within the oxide lattice) versus oxygen vacancy formation in tuning the electronic structure of molybdenum oxides while maintaining their high work function. A large improvement in the operational characteristics of both polymer light emitting devices and bulk heterojunction solar cells incorporating hydrogenated Mo oxides as hole injection/extraction layers was achieved as a result of favorable energy level alignment at the metal oxide/organic interface and enhanced charge transport through the formation of a large density of gap states near the Fermi level.
氧化钼在有机发光二极管和有机光伏等应用中被用作低电阻阳极界面层。然而，对于其化学计量比与其电子特性（如功函数和占据的间隙态）之间的相关性，人们知之甚少。此外，尽管确切的氧化物化学计量比的知识至关重要，但文献中很少有研究讨论如何控制这种化学计量比，以允许对氧化物的电子结构进行理想的修饰。本工作旨在研究氢化（将氢掺入氧化物晶格中）与氧空位形成相比，在调节氧化钼的电子结构的同时保持其高功函数方面的有益作用。结果表明，通过在金属氧化物/有机界面处实现有利的能级对准以及通过在费米能级附近形成大量的间隙态来增强电荷输运，作为空穴注入/提取层的氢化 Mo 氧化物的聚合物发光器件和体异质结太阳能电池的工作特性都得到了极大的改善。
