TY - JOUR

T1 - Interface formation between Cu-phthalocyanine films and US and GaAs semiconductor surfaces

AU - Komolov, A

AU - Moller, PJ

PY - 2004/5/31

Y1 - 2004/5/31

N2 - Total current electron spectroscopy (TCS) is applied as a key experimental technique to studies of electronic structure of organic semiconductor films interfacing inorganic semiconductors. Thin films of Cu-phthalocyanine (CuPc) were thermally deposited in UHV on CdS(000-1) and GaAS(100) substrates. The surface potential, the surface work function and the structure of unoccupied electron states (DOUS) located 5-25 eV above the Fermi level (E(F)) was monitored during the film deposition, using an incident beam of low-energy electrons according to the TCS method. Auger electron spectroscopy (AES) was used to monitor atomic composition of the surfaces under study. Electronic work function of the CuPc films changed during the film deposition until it reached a stable value 4.5 +/- 0.1 eV at the film thickness 8-10 nm. The deposition of the CuPc under 1.5 nm resulted in formation of the intermediate DOUS structures that were different for the cases of the two substrates used in the study. Fragments of the CuPc molecules were found to constitute mainly the intermediate deposit layers. Along with the increase of the deposit thickness to 8-10 nm, the intermediate DOUS structures were replaced by the DOUS structure typical for the CuPc film, although the S, Ga and As atoms migrated from the substrates were present in the CuPc film. Electron charge transfer layer at the CuPc/GaAs interface extended more than 5 nm from the GaAs surface, while the interaction at the CuPc/CdS interface resulted in band bending in the CdS subsurface region. (C) 2004 Elsevier B.V. All rights reserved.

AB - Total current electron spectroscopy (TCS) is applied as a key experimental technique to studies of electronic structure of organic semiconductor films interfacing inorganic semiconductors. Thin films of Cu-phthalocyanine (CuPc) were thermally deposited in UHV on CdS(000-1) and GaAS(100) substrates. The surface potential, the surface work function and the structure of unoccupied electron states (DOUS) located 5-25 eV above the Fermi level (E(F)) was monitored during the film deposition, using an incident beam of low-energy electrons according to the TCS method. Auger electron spectroscopy (AES) was used to monitor atomic composition of the surfaces under study. Electronic work function of the CuPc films changed during the film deposition until it reached a stable value 4.5 +/- 0.1 eV at the film thickness 8-10 nm. The deposition of the CuPc under 1.5 nm resulted in formation of the intermediate DOUS structures that were different for the cases of the two substrates used in the study. Fragments of the CuPc molecules were found to constitute mainly the intermediate deposit layers. Along with the increase of the deposit thickness to 8-10 nm, the intermediate DOUS structures were replaced by the DOUS structure typical for the CuPc film, although the S, Ga and As atoms migrated from the substrates were present in the CuPc film. Electron charge transfer layer at the CuPc/GaAs interface extended more than 5 nm from the GaAs surface, while the interaction at the CuPc/CdS interface resulted in band bending in the CdS subsurface region. (C) 2004 Elsevier B.V. All rights reserved.

KW - surface electronic phenomena

KW - electron-solid scattering and transmission-elastic

KW - surface chemical reaction

KW - semiconductor-organic

KW - semiconductor interfaces

KW - silicon

KW - silicon oxide

KW - Cu-phthalocyanine

KW - COPPER-PHTHALOCYANINE

KW - ELECTRONIC-STRUCTURE

KW - BAND-STRUCTURE

KW - PHOTOEMISSION

KW - PRINCIPLES

KW - ALIGNMENT

KW - DEVICES

KW - STATES

KW - LAYERS

U2 - 10.1016/j.colsurfa.2003.12.026

DO - 10.1016/j.colsurfa.2003.12.026

M3 - статья

VL - 239

SP - 49

EP - 54

JO - Colloids and Surfaces A: Physicochemical and Engineering Aspects

JF - Colloids and Surfaces A: Physicochemical and Engineering Aspects

SN - 0927-7757

IS - 1-3

Y2 - 14 May 2003 through 18 May 2003

ER -