EFFECT OF OXYGEN AND HYDROGEN PLASMA TREATMENT ON THE ROOM-TEMPERATURE SENSITIVITY OF SNO2 GAS SENSORS

The influence of oxygen plasma as well as hydrogen plasma on the gas s ensing properties of palladium doped SnO2 has been studied. It is foun d that the sensors treated in gaseous plasma become sensitive at room temperature and the sensitivity increases with the duration of exposur e in gaseous plasma. The sensitivity of sensors treated in oxygen plas ma is found to be about 10 times more than that of untreated sensor, w hile in the case of hydrogen plasma it is about seven times when treat ed for 15 min. The response and recovery time has also been studied. I t is found that both the response time and recovery time decrease with the increase in the duration of exposure time. The barrier height and effective barrier characteristics have also been evaluated through th e low temperature and impedance spectroscopic measurements. (C) 1998 E lsevier Science Ltd. All rights reserved.