Analysis of printed silver electrode on amorphous indium gallium zinc oxide

Silver (Ag) electrodes printed on amorphous indium gallium zinc oxide (a-InGaZnO) were investigated to analyze their effect on thin-film transistor (TFT) characteristics. The TFT characteristics of samples annealed at 250 °C deteriorated seriously owing to an aggregation of Ag. In addition, the TFT characteristics deteriorated even for 200 °C annealing with oxygen and nitrogen atmospheres. From measurements of secondary ion mass spectrometry and Fourier transform infrared spectroscopy, we found that carbon and hydrogen contained in printed Ag electrodes seriously affect the TFT characteristics. The reduction and protection against these impurities in Ag ink is the key point in the application of printed Ag electrodes to a-InGaZnO TFTs.