Influence of adsorbed oxygen on charge transport and chlorine gas-sensing characteristics of thin cobalt phthalocyanine films
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Soumen Samanta
,
Arvind Kumar
Abstract
We have investigated the morphology, charge transport, and gas-sensing characteristics of thin films of cobalt phthalocyanine (CoPc) deposited on glass and sapphire substrates, using molecular beam epitaxy (MBE). CoPc films deposited on glass were found to be highly disordered. The ambient oxygen was found to be chemisorbed and created deep trap states, which led not only to hysteretic current-voltage (J-V) characteristics but also reduce the charge mobility. These properties render them unsuitable for gas-sensing. On the other hand, films deposited on sapphire were polycrystalline, which was attributed to an improved molecule-substrate interaction. The physically sorbed oxygen only created shallow traps, and the J-V characteristics were non-hysteretic, rendering them suitable for gas-sensing applications. It was demonstrated that the ultrathin (20 nm) CoPc films deposited on sapphire acted as highly sensitive and selective sensors for chlorine present in the w Cl concentration range of 5 × 10−9−2 × 10−6 (5–2000 ppb).
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Articles in the same Issue
- Ultrathin organic, inorganic, hybrid, and living cell coatings — Topical Issue
- Functional polymer thin films designed for antifouling materials and biosensors
- In-situ polymerized molecularly imprinted polymeric thin films used as sensing layers in surface plasmon resonance sensors: Mini-review focused on 2010–2011
- Design of polyglycidol-containing microspheres for biomedical applications
- On the interfacial chemistry of aryl diazonium compounds in polymer science
- Polypyrrole coating of inorganic and organic materials by chemical oxidative polymerisation
- Spectroscopy of thin polyaniline films deposited during chemical oxidation of aniline
- Ultrathin functional films of titanium(IV) oxide
- Sol-gel thin films with anti-reflective and self-cleaning properties
- Nanostructured electrocatalysts immobilised on electrode surfaces and organic film templates
- Influence of adsorbed oxygen on charge transport and chlorine gas-sensing characteristics of thin cobalt phthalocyanine films
- Ni-W alloy coatings deposited from a citrate electrolyte
- Role of reactive species in processing materials at laboratory temperature by spray plasma devices
- Electrodeposition of hafnium and hafnium-based coatings in molten salts
- Role of interfacial chemistry on the rheology and thermo-mechanical properties of clay-polymer nanocomposites for building applications
- Endothelial cell adhesion on polyelectrolyte multilayer films functionalised with fibronectin and collagen
