A rare earth oxide (La2O3) has been used as gate insulator in CdSe Thin-film Transistors (TFTs) fabricated in staggered electrode structure by multiple pump down (MPD) method of vacuum evaporation. The device parameters are evaluated from the characteristics and the effect of ambient atmosphere is investigated through periodic monitoring of data. It is observed that the device characteristics deteriorated with time and ambient exposure contributed to faster deterioration
