Transport in high mobility amorphous wide band gap indium zinc oxide films

This paper discusses the electron transport in the n-type amorphous indium–zinc–oxygen system produced at room temperature by rf magnetron sputtering, under different oxygen partial pressures. The data show that the transport is not band tail limited, as it happens in conventional disordered semiconductors, but highly dependent on its ionicity, which explains the very high mobilities (≥60 cm2 V–1 s–1) achieved. The room temperature dependence of the Hall mobility on the carrier concentration presents a reverse behaviour than the one observed in conventional crystalline/polycrystalline semi-conductors, explained mainly by the presence of charged structural defects in excess of 4 × 1010 cm–2 that scatter the electrons that pass through them.