Orbital alignment at p-sexiphenyl and coronene/layered materials interfaces measured with photoemission spectroscopy

被引:52
作者
Schroeder, PG
France, CB
Parkinson, BA
Schlaf, R
机构
[1] Univ S Florida, Dept Elect Engn, Ctr Microelect Res, Tampa, FL 33620 USA
[2] Colorado State Univ, Dept Chem, Ft Collins, CO 80523 USA
关键词
D O I
10.1063/1.1473217
中图分类号
O59 [应用物理学];
学科分类号
摘要
The energy level alignment at the interfaces between para-sexiphenyl/highly oriented pyrolytic graphite (HOPG), coronene/SnS2, and coronene/HOPG were determined using in situ thin film deposition in combination with x-ray photoelectron spectroscopy (XPS) and ultraviolet photoemission spectroscopy (UPS) measurements. The organic thin films were grown in multiple steps by vapor deposition, then sequentially characterized in situ after each growth step. The vacuum cleaved single crystals of SnS2 and HOPG substrates provided clean, atomically flat, and chemically inert surfaces, allowing for the investigation of the phenomena of band bending and interface dipoles without the interference of chemical reactions or morphological problems. Due to the distinctly different work functions of the HOPG (Phi = 4.65 eV) and SnS2 (Phi = 5.45 eV) substrates, the observed shifts in the binding energies of the organic overlayer related XPS core level emission lines could be associated with band bending resulting from Fermi level equilibration between the organic thin films and substrates. Possible occurrence of screening effects due to the different polarization energies of the two substrates can, however, complicate the ability to precisely measure band bending. Low intensity XPS work function measurements enabled the detection of the overlayer-thickness-dependent onset of charging phenomena in the UPS measurements. This allowed the precise determination of the highest occupied molecular orbital alignment of the organic molecules at the investigated interfaces. (C) 2002 American Institute of Physics.
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页码:9095 / 9107
页数:13
相关论文
共 57 条
[1]   ADSORBED LAYER AND THIN-FILM GROWTH MODES MONITORED BY AUGER-ELECTRON SPECTROSCOPY [J].
ARGILE, C ;
RHEAD, GE .
SURFACE SCIENCE REPORTS, 1989, 10 (6-7) :277-356
[2]   SOFT-X-RAY DAMAGE TO P-TERPHENYL COATINGS FOR DETECTORS [J].
BENITEZ, EL ;
DARK, ML ;
HUSK, DE ;
SCHNATTERLY, SE ;
TARRIO, C .
APPLIED OPTICS, 1994, 33 (10) :1854-1856
[3]   Effect of growth temperature and substrate materials on epitaxial growth of coronene [J].
Cho, KA ;
Shimada, T ;
Sakurai, M ;
Koma, A .
JOURNAL OF APPLIED PHYSICS, 1998, 84 (01) :268-274
[4]   POLYMERS AND MOLECULAR SOLIDS - NEW FRONTIERS IN SURFACE SCIENCE [J].
DUKE, CB .
SURFACE SCIENCE, 1978, 70 (01) :674-691
[5]   EPITAXIAL THIN-FILMS OF LARGE ORGANIC-MOLECULES - CHARACTERIZATION OF PHTHALOCYANINE AND CORONENE OVERLAYERS ON THE LAYERED SEMICONDUCTORS MOS2 AND SNS2 [J].
ENGLAND, CD ;
COLLINS, GE ;
SCHUERLEIN, TJ ;
ARMSTRONG, NR .
LANGMUIR, 1994, 10 (08) :2748-2756
[6]   POLARIZED ELECTROLUMINESCENCE FROM ORIENTED P-SEXIPHENYL VACUUM-DEPOSITED FILM [J].
ERA, M ;
TSUTSUI, T ;
SAITO, S .
APPLIED PHYSICS LETTERS, 1995, 67 (17) :2436-2438
[7]   REALIZATION OF A BLUE-LIGHT-EMITTING DEVICE USING POLY(PARA-PHENYLENE) [J].
GREM, G ;
LEDITZKY, G ;
ULLRICH, B ;
LEISING, G .
ADVANCED MATERIALS, 1992, 4 (01) :36-37
[8]   Characterization of X-ray induced damage in alkanethiolate monolayers by high-resolution photoelectron spectroscopy [J].
Heister, K ;
Zharnikov, M ;
Grunze, M ;
Johansson, LSO ;
Ulman, A .
LANGMUIR, 2001, 17 (01) :8-11
[9]   Distinguishing between interface dipoles and band bending at metal/tris-(8-hydroxyquinoline) aluminum interfaces [J].
Hill, IG ;
Mäkinen, AJ ;
Kafafi, ZH .
APPLIED PHYSICS LETTERS, 2000, 77 (12) :1825-1827
[10]   Energy-level alignment at interfaces between metals and the organic semiconductor 4,4′-N,N′-dicarbazolyl-biphenyl [J].
Hill, IG ;
Rajagopal, A ;
Kahn, A .
JOURNAL OF APPLIED PHYSICS, 1998, 84 (06) :3236-3241