Transparent conducting films grown by pulsed laser deposition

We have studied the properties of two types of transparent conducting oxides grown by pulsed laser deposition (PLD) on quartz substrates. We have grown films of ITO with resistivity as low as 250 μΩ-cm and with absorption coefficient < 600 cm^-1 throughout the visible spectrum. Even films deposited at room temperature can have P < 500 μΩ-cm, although the optical transmission characteristics are worse than those of commercially available ITO. Important parameters governing film quality include the oxygen partial pressure during film deposition and substrate temperature. GaInO₃ is a recently identified transparent conducting material which is structurally distinct from ITO. Films have been grown with no intentional dopants and with either Ge substitution for Ga or Sn substitution for In. Doping concentrations as high as 10 at. % have been studied. There is no evidence for dopant segregation. Films with resistivities as low as 3 mΩ-cm have been achieved, and the absorption coefficient can be less than 500 cm^-1 throughout the entire visible spectrum.