Temperature effects on sputtered ITO

Indium Tin Oxide (ITO) is widely used in solar cell devices for its excellent electrical and optical characteristics, such as high transparency in the Ultraviolet-Visible range and good conductivity (around 10
⁴
W
^-1
cm
^-1
). In this work we have compared thin (70-150 nm) ITO layers deposited by Direct Current or Radio Frequency sputtering. We have used different substrate temperatures during film growth and have afterwards thermally annealed the samples at different temperatures up to 300 °C to investigate the effects on the electrical and optical properties of the material. We have found out that the different growth/annealing conditions induce changes in the optical properties of the samples as well as in the conductivity and carrier concentration.