Gas sensors based on γ-Fe 2 O 3 and CoFe 2 O 4 nanoparticles (NPs) were prepared by Langmuir-Schaeffer deposition onto Al 2 O 3 and auxilliary Si substrates. NPs with the size of 6.4 nm (Fe 2 O 3 ) and 7.6 nm (CoFe 2 O 4 ) and polydispersity of 9 % were fabricated by chemical route. NP arrays were analyzed by GIXRD, SEM, TEM, DLS and ellipsometry. Fe 2 O 3 sensors show high response of 38 for 500 ppb of strongly oxidizing NO 2 . The response of CoFe 2 O 4 sensors is 10 at 5 ppm of NO 2 . Sensitivities are lower with reducing CO and acetone gases. After one year storage at room temperature, a 6 % decrease of response was found. The sensor sensitivities are discussed comparing with the best published results so far.
20 Oct 2014
The Tenth International Conference on Advanced Semiconductor Devices and Microsystems