Charge Transport Characteristics Of Cobalt Phthalocyanine Thin Films Grown By Molecular Beam Epitaxy

Journal Article · Wed Dec 01 00:00:00 EST 2010 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3530568· OSTI ID:21509981

Gupta, S K; Singh, Ajay; Samanta, Soumen; Kumar, Arvind; Debnath, A K; Aswal, D K ^[1]

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1. Technical Physics Division, Bhabha Atomic Research Center, Mumbai 400 085 (India)

In the recent times organic semiconductors (OSC) have received attention because of their application in low-cost, flexible, and large area electronics devices. The application of OSC thin films has been limited due to their low charge carrier mobility ({approx}0.1 cm{sup 2}/V-s). We have investigated the effect of substrate on structure and charge transport characteristics of cobalt phthalocyanine (CoPc) films. Thin films have been grown on both single crystal (sapphire and LaAlO{sub 3}) and amorphous (quartz) substrates using molecular beam epitaxy system. The films grown on LaAlO{sub 3} substrates exhibited a higher value of mobility ({approx}4 cm{sup 2}/V-s) while those grown on Al{sub 2}O{sub 3} and quartz showed mobility value of {approx}1 cm{sup 2}/V-s. High mobility for LaAlO{sub 3} substrates has been attributed to the enhanced ordering of the molecules due to natural twin boundaries of substrates. In order to further confirm role of grain boundaries in aligning the CoPc molecules, we measured the charge transport on films deposited at bi-crystal SrTiO{sub 3} substrates. The results showed that current along bi-crystal grain boundary is three orders of magnitude higher than for films on SrTiO{sub 3} substrate without grain boundary, which confirms our hypothesis of ordering of molecules along grain boundaries.

• OSTI ID: 21509981
• Journal Information: AIP Conference Proceedings, Vol. 1313, Issue 1; Conference: PEFM-2010: International conference on physics of emerging functional materials, Mumbai (India), 22-24 Sep 2010; Other Information: DOI: 10.1063/1.3530568; (c) 2010 American Institute of Physics; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINATES
ALUMINIUM OXIDES
AMORPHOUS STATE
CHARGE CARRIERS
CHARGE TRANSPORT
COBALT COMPOUNDS
GRAIN BOUNDARIES
LANTHANUM COMPOUNDS
MOBILITY
MOLECULAR BEAM EPITAXY
MOLECULES
MONOCRYSTALS
ORGANIC SEMICONDUCTORS
QUARTZ
SAPPHIRE
SCANNING ELECTRON MICROSCOPY
STRONTIUM TITANATES
SUBSTRATES
THIN FILMS
X-RAY DIFFRACTION
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM COMPOUNDS
CHALCOGENIDES
COHERENT SCATTERING
CORUNDUM
CRYSTAL GROWTH METHODS
CRYSTALS
DIFFRACTION
ELECTRON MICROSCOPY
EPITAXY
FILMS
MATERIALS
MICROSCOPY
MICROSTRUCTURE
MINERALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
RARE EARTH COMPOUNDS
SCATTERING
SEMICONDUCTOR MATERIALS
STRONTIUM COMPOUNDS
TITANATES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS