Conductometric gas sensing studies of tert-butyl silicon-[bis ethyloxy]-phthalocyanine LB films
- 124 Downloads
Ultrathin Langmuir-Blodgett film properties of tert-butyl silicon-[bis ethyloxy]-phthalocyanine (tbPcSi(OC2 H5)2) have been studied and characterised. Surface pressure–area isotherms reveal an area per molecule of around 0.85 nm2, and that a compact ‘solid’ phase occurs in the region 10–30 m N m−1. LB films of different thicknesses were deposited onto gold interdigitated electrodes on glass in order to facilitate I–V measurements and assess the conductometric sensing properties in response to 5 ppm NO2. The I–V characteristic is Ohmic and yields conductivity in the range comparable to that obtained for other phthalocyanine monomers. The gas sensing behaviour of these films in response to NO2 was investigated and modelled using a double exponential model. Preliminary UV–visible spectroscopic investigations indicate that the film also responds optically.
KeywordsPhthalocyanine CoPc FePc NiPc Langmuir Blodgett Film
AF would like to thank Mr Alex McNaughton for the use of the Accerlys software and Dr Alan Dunbar for helpful discussions.
- 1.McKeown N (1998) Phthalocyanine materials. Cambridge University Press, UKGoogle Scholar
- 3.Richardson T (2000) Functional organic and polymeric materials. Wiley and Sons, LtdGoogle Scholar
- 4.Oleinick NL, Zaidi SI, Rihter BD, Kenny ME, Clay ME, Antunez AR, Mukhtar H (1992) Proceeedings of the SPIE, vol 1645, p 242Google Scholar
- 8.Twigg MV, Baker S, Petty MC, Roberts GG (1983) Thin Solid Films 99(1–3):53Google Scholar
- 25.Thorpe SC, Crouch D, Cook MJ, Chambrier I, Ray AK (1994) Sensor Actuator B 18–19:411Google Scholar