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Title: STRUCTURE AND ELECTRONIC PROPERTIES OF SELF-ASSEMBLED MACROCYCLE AND POLYMER MULTILAYERS

Our results from optical absorption and surface external reflection FTIR reveal that we can grow self-assembled multilayers consisting of electron acceptors like OHBP and donors like NiPc. In order to investigate the evolution of the surface physical properties of self-assembled multilayers, we applied Kelvin probe techniques and surface photovoltage spectroscopy to monitor the growth of self-assembled OHBP and NiPc systems. Kelvin probe results indicate that the surface electronic potential is very sensitive to the presence of self-assembled molecular layers on surfaces. We find that there is an approximately constant gap of 350 meV between the surface work function of OHBP and NiPc terminated self-assembled multilayers. In other words, the surface work function or surface electronic potentials is a periodic function of the terminating layer, oscillating between {approximately}450 mV for OHBP layers and {approximately}100 mV for NiPc layers. On the other hand, the photo-induced effects can be also correlated to the terminating layer of the OHBP-NiPc system. This shows that the self-assembled layers also control the photo-induced effects to some extent. Over the whole excitation spectrum (300-710 nm), the photo-induced band bending change oscillates between two values mostly governed by the properties of the terminating layer of the self-assembled systems.
Authors:
;
Publication Date:
OSTI Identifier:
780813
Report Number(s):
LA-UR-01-2637
TRN: AH200124%%162
DOE Contract Number:
W-7405-ENG-36
Resource Type:
Conference
Resource Relation:
Conference: Conference title not supplied, Conference location not supplied, Conference dates not supplied; Other Information: PBD: 1 May 2001
Research Org:
Los Alamos National Lab., NM (US)
Sponsoring Org:
US Department of Energy (US)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ABSORPTION; BINDING ENERGY; ELECTRONS; MONITORS; PHYSICAL PROPERTIES; POLYMERS; PROBES; REFLECTION; SPECTROSCOPY; VALENCE; WORK FUNCTIONS