The effect of operating modes on the response of ammonia sensors based on tin dioxide films

The influence of operating modes on the response of ammonia sensors based on tin dioxide films has been studied. Samples have been obtained as a result of high-frequency magnetron sputtering of a SnO$_2$:Sb target on sapphire substrates with predeposited Pt electrodes and a heater. Varying the heating cycle duration and reducing the cooling cycle temperature may increase the response by one or two orders of magnitude. The results are explained as being due to the change in the density of chemically adsorbed oxygen on the surface of the SnO$_2$:Sb film depending on the temperature regime.