J. Phys. IV France 09 (1999) Pr8-643-Pr8-650
MOCVD and properties of in situ doped Pt-SnO2 thin filmsM. Amjoud1 and F. Maury2
1 Faculté des Sciences et Techniques de Gueliz, Département de Chimie, BP. 618, 40000 Marrakech, Maroc
2 Laboratoire Interfaces et Matériaux, CNRS/INPT, École Nationale Supérieure de Chimie, 118 route de Narbonne, 31077 Toulouse cedex 4, France
Intrinsic and in situ Pt-doped SnO2 thin films were deposited in the temperature range 320-440 °C by MOCVD using SnEt4 and Pt(hfa)2 as metal-organic precursors and O2 as added oxidant. The growth rate is slightly inhibited by addition of dopant molecules and the process is thermally activated. The Pt content of the films increases with Pt(hfa)2 mole fraction and the growth temperature. Typically, layers containing 0.8 at. % Pt have been prepared at 380 °C. Platinum is uniformly distributed through the thickness of the films. The good efficiency of this in situ doping process is revealed by the decrease of the room temperature resistivity as the Pt content of the films increases. Pt-SnO2 layers exhibit a thermal stability higher than that of undoped films. Preliminary responses as gas sensor have shown that the detection sensitivity to ethanol in dry air is increased by a factor higher than 2 for Pt-doped SnO2 relative to undoped layers.
© EDP Sciences 1999