利用STM和CV方法测定有机发光材料的能带参数  

Energy-band Structures of Organic Light-emitting Materials by STM and Cyclic Voltammetry

作　　者：付慧英[1] 邱伟民[1] 蔡臻炜[1] 肖斐[1] 邵丙铣[1] 

机构地区：[1]复旦大学材料科学系,上海200433

出　　处：《发光学报》2006年第4期566-570,共5页Chinese Journal of Luminescence

基　　金：上海市科委资助项目(015261049)

摘　　要：利用扫描隧道显微镜/扫描隧道谱(STM/STS)的技术,研究了有机发光材料A lq3、DPN-2CN和DNP-2CN的表面电子结构。将材料DPN-2CN和DNP-2CN的表面电子结构与A lq3的表面电子结构进行对比,判定了DPN-2CN和DNP-2CN的最低空轨道(LUMO)能级。通过电化学循环伏安(CV)法,对DPN-2CN和DNP-2CN的LUMO能级和最高占有轨道(HOMO)能级进行了表征。两种测试方法所得到的LUMO能级参数基本一致。Scanning probe microscopy offers the possibility of probing physical properties with high spatial resolution. In particular, scanning tunneling microscopy （STM） and scanning tunneling spectroscopy （STS） can be used to combine structural characterization with probing the electronic signature of the organic compounds on a molecular scale. A number of STS investigations on organic materials have been published in recent years. And most of the authors observed electron transport through the frontier orbitals of the organic molecules （ i. e. , through the highest occupied molecular orbital （HOMO） and the lowest unoccupied molecular orbital （LUMO）. The measurements of the contributions of the second filled and second unfilled molecular orbitals to the tunneling current have also been studied in a few researches. Compared with other methods of molecular energy structure characterization, such as Ultraviolet-Visible Spectrophotometry （UV-Vis）, Cyclic Vohammetry （CV） and Ultraviolet Photoelectron Spectroscopy （UPS）, STM/STS can show the nanosized surface microscopy of the molecule in real time and the detailed information of surface roughness and graininess of the thin solid film can be obtained. The STM/STS measurement has become a powerful tool for the study of nanostructures in numerous areas of science and technology. The application of STM/STS in the field of organic light-emitting diodes （OLEDs） is promising. We present here a study of vapor deposition thin film layers of tris （ 8-hydroxyquinolino ） aluminum （ Alq3 ）, 4-（ 2-（ 3,3-dicyano-methylene-5,5-dimethyl-1-cyclo-hexylidene） vinyl） phenyl （ 1 -naphthyl ） phenyl-amine （ DPN-2CN ）, and 4-（ 2-（ 3,3-dicyano-methylene- 5,5-dimethyl-1 -cyclohexyl-idene） vinyl） phenyldi （ 1 -naphthyl） - amine （ DNP-2CN ） on the substrate of ITO. The surface electronic structures of organic light-emitting materials Alq3, DPN-2CN and DNP-2CN were studied by STM/STS. The obtained ELUMO of compound DPN-2CN were 3.50

关 键 词：有机发光材料 扫描隧道显微镜 扫描隧道谱 电化学 循环伏安 

分 类 号：O646[理学—物理化学] TN873.3[理学—化学]