Alq_3/ITO结构的表面和界面电子状态的XPS研究  

XPS Investigation of Surface and Interface Electronic States of Alq_3/ITO

作　　者：郑代顺[1] 李海蓉[1] 王延勇[1] 张福甲[1] 

机构地区：[1]兰州大学物理学院,甘肃兰州730000

出　　处：《发光学报》2001年第4期351-356,共6页Chinese Journal of Luminescence

基　　金：国家自然科学基金资助项目(60076023)

摘　　要：用传统的真空蒸镀法制备了Ａｌｑ３／ＩＴＯ样品，并用Ｘ光电子能谱（ＸＰＳ）研究了Ａｌｑ３／ＩＴＯ紧密接触的表面和界面电子化学状态。对Ａｌｑ３／ＩＴＯ样品的表面分析表明，在ｌｑ３分子中，Ａｌ原子的束缚能（Ｅｂ）为７０．７ｅＶ和７５．１ｅＶ。分别对应于Ａｌ（０）和Ａｌ（Ⅲ）态，Ｃ原子的束缚能为２８５．８ｅＶ、２８６．３ｅＶ和２８６．８ｅＶ，分别对应于Ｃ－Ｃ、Ｃ－Ｏ和Ｃ－Ｎ键；Ｎ原子的主峰位于 ４０１．０ｅＶ，对应于 Ｃ－Ｎ＝Ｃ键；而 Ｏ原子主要与 Ｈ原子成键，其束缚能为５３２．８ｅＶ。为了研究Ａｌｑ３／ＩＴＯ的界面电子状态，我们用氩离子束对样品表面进行了溅射剥蚀，当溅射时间分别为３０，３５，４５分钟时进行ＸＰＳ采谱分析。结果表明，随着氩离子束溅射时间增长，Ａｌ２ｐ、Ｃ１ｓ、Ｎ１ｓ、Ｏ１ｓ、Ｉｎ３ｄ５／２和Ｓｎ３ｄ５／２峰都向低束缚能方向有微小移动，且Ａｌ２ｐ、Ｃ１ｓ和Ｎ１ｓ峰变弱，这是受ＩＴＯ中扩散进入Ａｌｑ３层的Ｏ、Ｉｎ和Ｓｎ原子的影响所致。An understanding of the surface and interface states of the organic material and the underlying anode material is meaningful for organic light-emitting devices (OLEDs). The tris-(8-hydroxyquinoline) aluminum (A1q3)/indium-tin oxide (ITO) samples were fabricated with traditional vacuum deposition. The surface and interface electronic chemical states of the A1q3 and the underlying ITO have been investigated by X-ray photoelectron spectroscopy (XPS). The analysis on XPS spectra of the surface of the Alq3/ITO structure shows that, in Alq3 molecule, the binding energy (Eb) of Al atoms is 70.7eV and 75.1eV, corresponding to Al (0) and Al (Ⅲ), respec- tively. The binding energy of C atoms is 285. 8eV, 286. 3eV and 286. 8eV, corresponding to C atoms of C- C groups, C-O and C-N bonds, respectively. The N1s main peak locates at 401 .0eV, corresponding to N atoms of C-N = C bonds. O atoms mainly bond to H atoms, and the bonding energy is 532. 8eV. The N and O atoms also interact with Al atoms through coordination bonds. In order to investigate the interface electronic states of the Alq3/ ITO structure, the samples are sput- tered by argon ions beam. The analysis on XPS spectra of the interface of the A1q3/ITO structure indicates that, as the sputtering time of argon ions beam increasing, Al2p, C1s and N1s peaks get weaker, which in- dicates the Alq3 film becomes thinner and thinner and the concentrations of the Al, C and N atoms reduce with increasing sputtering time. The core-levels of Al2p, C1s, N1s, O1s, In3d5/2 and Sn3d5/2 spectra slightly shift towards lower binding energy when the sputtering time increasing, this may be caused by the effect of oxygen, indium and tin in ITO diffusing into Alq3 layer and the argon ions beam with high energy. Besides these, with the sputtering time of argon ions beam increasing, the relative concentration of O atoms from ITO diffusing into A1q3 increases, and the interaction of O atoms with In and Sn atoms gradually re- duces, which results in the In2O3 and SnO2 turning int

关 键 词：Alq3/ITO XPS 结构 表面电子状态 界面电子状态 电致发光器件 8-羟基喹啉铝 发光材料 

分 类 号：TN383.1[电子电信—物理电子学] TN104.3