TY - JOUR

T1 - Interface formation between thin Cu-phthalocyanine films and crystalline and oxidized silicon surfaces

AU - Komolov, A.S.

AU - Moller, P.J.

PY - 2002/4/30

Y1 - 2002/4/30

N2 - Thin films of Cu-phthalocyanine (CuPc) were thermally deposited in UHV on n-Si(1 0 0) and SiO2/n-Si substrates. Evolution of the surface potential and density of unoccupied electronic states located 0-25 eV above vacuum level were measured during the film deposition using an incident beam of low energy electrons using total current electron spectroscopy (TCS), and a new approach based on TCS analysis was developed and applied to studies of charge transfer at the interfaces. The analysis showed that a negative electric charge was transferred from the film to the substrate. A positively charged layer was registered in the CuPc films, which extends over a range from the substrate level and up to 10 nm. At a higher film thickness, bulk Cape films were formed that have a workfunction of 4.5 +/- 0.1 cV. CuPc molecules decompose on the n-Si(1 0 0) substrate due to interaction with the crystalline surface while the film thickness is less than 3 nm. The features of the interfaces observed during formation of the interfaces are analyzed and a model for the extended charge-transfer layer (extended interface dipole) is applied. (C) 2002 Elsevier Science B.V. All rights reserved.

AB - Thin films of Cu-phthalocyanine (CuPc) were thermally deposited in UHV on n-Si(1 0 0) and SiO2/n-Si substrates. Evolution of the surface potential and density of unoccupied electronic states located 0-25 eV above vacuum level were measured during the film deposition using an incident beam of low energy electrons using total current electron spectroscopy (TCS), and a new approach based on TCS analysis was developed and applied to studies of charge transfer at the interfaces. The analysis showed that a negative electric charge was transferred from the film to the substrate. A positively charged layer was registered in the CuPc films, which extends over a range from the substrate level and up to 10 nm. At a higher film thickness, bulk Cape films were formed that have a workfunction of 4.5 +/- 0.1 cV. CuPc molecules decompose on the n-Si(1 0 0) substrate due to interaction with the crystalline surface while the film thickness is less than 3 nm. The features of the interfaces observed during formation of the interfaces are analyzed and a model for the extended charge-transfer layer (extended interface dipole) is applied. (C) 2002 Elsevier Science B.V. All rights reserved.

KW - Cu-phthalocyanine

KW - n-Si

KW - silicon oxide

KW - interface charge transfer

KW - electron spectroscopy

KW - TARGET CURRENT SPECTROSCOPY

KW - ENERGY-LEVEL ALIGNMENT

KW - ELECTRONIC-STRUCTURES

KW - COPPER-PHTHALOCYANINE

KW - BAND-STRUCTURE

KW - STATES

KW - LAYERS

M3 - статья

VL - 128

SP - 205

EP - 210

JO - Synthetic Metals

JF - Synthetic Metals

SN - 0379-6779

IS - 2

M1 - PII S0379-6779(02)00017-6

ER -