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Title: Structurally induced large changes of the energy level alignment in CuPc on Cu ( 110 ) - ( 2 × 1 ) O

While it is becoming apparent that organic semiconductor/metal interfaces may exhibit a variety of different structural phases, it is at present unclear to what extent these different thin-film structures determine the interfacial electronic structure. Here, we observe large changes in the interfacial electronic structure for the case of copper(II) phthalocyanine (CuPc) on Cu(110)–(2×1)O. This striking evolution of the interfacial electronic structure occurs beyond the first monolayer of CuPc and is particularly evident in the frontier orbital region. Using scanning tunneling microscopy in conjunction with photoemission spectroscopy, we characterize ultrathin films of CuPc grown on oxygen reconstructed Cu(110). We propose that the observed unique changes to the electronic structure result from an abrupt transition in film structure between the first and second layers: An interface layer of ordered, face-on molecules templates a largely vertical, edge-on orientation of molecules in the subsequent layer. The quadrupole moment of the molecule accounts for the sizable and unusual change in ionization energy between molecules in the two layers. Lastly, our results demonstrate that the precise structure of the organic semiconductor film exerts an important role in determining the interfacial electronic structure that must be considered and may be harnessed for tailoring energy level alignment atmore » such interfaces.« less
Authors:
 [1] ;  [1] ;  [2] ;  [1]
  1. Univ. of Arizona, Tucson, AZ (United States)
  2. Brookhaven National Lab. (BNL), Upton, NY (United States)
Publication Date:
Report Number(s):
BNL-209147-2018-JAAM
Journal ID: ISSN 2469-9950; PRBMDO
Grant/Contract Number:
SC0012704
Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 98; Journal Issue: 15; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY
OSTI Identifier:
1476760
Alternate Identifier(s):
OSTI ID: 1475236

Maughan, Bret, Eads, Calley N., Zahl, Percy, and Monti, Oliver L. A.. Structurally induced large changes of the energy level alignment in CuPc on Cu(110)-(2×1)O. United States: N. p., Web. doi:10.1103/PhysRevB.98.155106.
Maughan, Bret, Eads, Calley N., Zahl, Percy, & Monti, Oliver L. A.. Structurally induced large changes of the energy level alignment in CuPc on Cu(110)-(2×1)O. United States. doi:10.1103/PhysRevB.98.155106.
Maughan, Bret, Eads, Calley N., Zahl, Percy, and Monti, Oliver L. A.. 2018. "Structurally induced large changes of the energy level alignment in CuPc on Cu(110)-(2×1)O". United States. doi:10.1103/PhysRevB.98.155106.
@article{osti_1476760,
title = {Structurally induced large changes of the energy level alignment in CuPc on Cu(110)-(2×1)O},
author = {Maughan, Bret and Eads, Calley N. and Zahl, Percy and Monti, Oliver L. A.},
abstractNote = {While it is becoming apparent that organic semiconductor/metal interfaces may exhibit a variety of different structural phases, it is at present unclear to what extent these different thin-film structures determine the interfacial electronic structure. Here, we observe large changes in the interfacial electronic structure for the case of copper(II) phthalocyanine (CuPc) on Cu(110)–(2×1)O. This striking evolution of the interfacial electronic structure occurs beyond the first monolayer of CuPc and is particularly evident in the frontier orbital region. Using scanning tunneling microscopy in conjunction with photoemission spectroscopy, we characterize ultrathin films of CuPc grown on oxygen reconstructed Cu(110). We propose that the observed unique changes to the electronic structure result from an abrupt transition in film structure between the first and second layers: An interface layer of ordered, face-on molecules templates a largely vertical, edge-on orientation of molecules in the subsequent layer. The quadrupole moment of the molecule accounts for the sizable and unusual change in ionization energy between molecules in the two layers. Lastly, our results demonstrate that the precise structure of the organic semiconductor film exerts an important role in determining the interfacial electronic structure that must be considered and may be harnessed for tailoring energy level alignment at such interfaces.},
doi = {10.1103/PhysRevB.98.155106},
journal = {Physical Review B},
number = 15,
volume = 98,
place = {United States},
year = {2018},
month = {10}
}

Works referenced in this record:

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