Electron spectroscopy studies of interface formation between metal electrodes and luminescent organic materials
Electron spectroscopy studies of interface formation between metal electrodes and luminescent organic materials
复制标题
金属电极与发光有机材料之间界面形成的电子能谱研究
DOI：
10.1116/1.580774
复制
发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Yongli Gao
中科院分区：
文献类型：
--
作者：
Yongsup Park;V. Choong;B. Hsieh;C. Tang;T. Wehrmeister;K. Müllen;Yongli Gao
利用x射线和紫外光电子能谱（XPS和UPS）研究了有机电致发光器件中金属/有机界面的形成。以低聚对苯基乙烯（OPV）和三-（8-羟基喹啉）铝（Alq3）为有机材料，以Ca为金属层。将有机层沉积在Ca和将Ca沉积在有机衬底上形成不同的界面。对于Ca/OPV， UPS显示了Ca沉积后界面态形成的明确证据。XPS核能级峰随Ca层厚度的变化与能级弯曲图一致。OPV/Ca的XPS和UPS光谱作为有机层厚度的函数也证实了能级弯曲。得到的数据使我们可以推导出界面附近的能级图。Alq3/Ca的类似数据表明，如果用文献中的Alq3光学带隙来估计能量正数，则在该界面上不存在电子注入势垒。
Using x-ray and ultraviolet photoelectron spectroscopy (XPS and UPS), we have studied the formation of metal/organic interfaces in organic electroluminescent devices. Oligo(p-phenylenevinylenes) (OPV) and tris-(8-hydroxyquinoline)aluminum (Alq3) were used as the organic materials and Ca was used as the metallic layer. Interfaces are formed differently by depositing organic layer on Ca and Ca on organic substrate. For Ca/OPV, UPS revealed a clear evidence for interface state formation upon Ca deposition. The evolution of XPS core level peak as a function of Ca layer thickness was consistent with the energy level bending picture. The XPS and UPS spectra for OPV/Ca as a function of organic layer thickness also confirmed the energy level bending. The data obtained allowed us to deduce the energy level diagram near the interface. Similar data for Alq3/Ca indicated that no electron injection barrier exists at this interface if the Alq3 optical band gap in the literature was used for estimating the energy positi...