Disorder and instability processes in amorphous conducting oxides

The behaviour of ionic amorphous oxide semiconductors (transparent conducting oxides) such as In2O3, SnO2, and ZnO is contrasted with that of covalent amorphous semiconductors such as amorphous Si. These oxides have an s-like conduction band minima, which leads to high electron mobilities, smaller effects of disorder, and the ability to move the Fermi level well into the conduction band. This results in an absence of the bias stress instability due to the bond breaking mechanism in oxide thin film transistors, which limited the stability of a-Si:H transistors.