共轭聚合物和共轭有机分子电子能级的测量

Measurement of Electronic Energy Levels of Conjugated Polymers and Organic Molecules

近年来,有机发光二极管(OLED)和有机太阳电池(OSC)等有机光电器件步入快速发展阶段,受到广泛关注.而有机半导体的电子能级(HOMO和LUMO能级)与电极功函数的匹配对其光电性能至关重要,它决定着OLED电极电荷注入的能垒和OSC电极电荷收集的能垒.另外,OSC中给体材料和受体材料电子能级的匹配对其光伏性能也非常重要.因而,准确测量有机半导体光电材料的电子能级非常重要.本文将介绍测量有机半导体电子能级常用的紫外光电子能谱和电化学方法,从测量原理、样品制备、测量注意事项等方面详细介绍了有机半导体电子能级的测量与计算.我们给出了几个共轭聚合物和共轭有机小分子等有机半导体电子能级测量的实例,并列举了部分典型有机半导体材料已报道的电子能级数据以供读者参考.

In recent years,organic optoelectronic devices,including organic light emitting diodes(OLEDs)and organic solar cells(OSCs),have attracted great attention and developed rapidly.The matching of the electronic energy levels(HOMO and LUMO energy levels)of the organic semiconductors with the work-functions of the electrodes is of great importance for the optoelectronic properties of the devices.In addition,the matching of the HOMO and LUMO energy levels of the donor and acceptor materials is also crucial for the photovoltaic performance of the OSCs.Therefore,it is very important to accurately measure the HOMO and LUMO energy levels of the organic semiconductors.In this paper,we will introduce the commonly used measurement methods of the electronic energy levels of the organic semiconductors,including ultraviolet photoelectron spectroscopy(UPS)and electrochemical methods.And we will explain the measurement mechanism,sample preparation,attention items of the measurements,and give the calculation equations of the electronic energy levels.We also give several examples to measure the energy levels of the organic semiconductors including conjugated polymers and conjugated organic small molecule semiconductors,and liste the HOMO and LUMO energy levels of some typical organic semiconductor materials reported in literatures,for the reference of the readers.