Transparent conducting oxides are a special class of material which exhibit a remarkable good electrical conductivity (~103S/cm) like metals and remarkable good optical transmittance (>80%) in visible and IR region. Generally, oxides are assumed to be an insulator due to their large bandgap but TCO is exceptional oxides. Due to this idiosyncratic property, they are devastatingly used in Research and industry.
So far they are generally found in crystalline nature but recently a new group of conventional TCOs is proposed which are amorphous in nature having comparable optoelectronic properties as crystalline TCOs giving the advantage of being flexible as well. The easy and cheap fabrication technique is an essential step to make them usable widely. Physical vapor deposition (PVD) techniques are used at a large scale in the fabrication of TCO thin films which used as an electrode in the passive devices like a photovoltaic, organic light-emitting diode (OLED) and active layer inactive devices like thin-film transistor (TFT).