NO2 sensing properties of Nano structured ITO thin film

K.VijayLakshmi and C.Ravidhas

Department of Physics, Bishop Heber College, Tiruchirappali, (India).

Received on October 30, 2009 and accepted on December 02, 2009

ABSTRACT

ITO is the most commonly used semi conducting materials for sensor devices. In the present work. Transparent conducting ITO films have been deposited on to glass substrates by rf magnetron sputtering at 648k Temperature under an oxygen partial pressure of 10x10-3 mbar, The deposition condition necessary to produce ITO films with high conductivity and optical transparency over a wide spectral range were studied and optimized. The more influential factors determining the optical and electrical properties including partial pressure of the reactive gas The sputtering power as well as other growth related effects is analyzed. Transmission was measured with perkin – Elmer – UV/VIS lambda 40 spectrometer and electrical studies using four probe and Hall effect setup. Structural characterization of the films has been done by XRD. Characterization of the coatings revealed specific receptivity’s below 6.5 10-3W. Films deposited without annealing were amorphous and the crystallinity improved after annealing at 700k. the optical transmittance of the SEM appears to be uniform over large surface areas. The correlations among properties of the film and its influence on heat treatment have been analyzed. The obtained results have been used for a better comprehension of the gas – sensing properties towards. NO2.

Keywords : ITO sputtering parameters, annealing, NO2 Gas sensor.