Structural, electrical, and optical properties of ZnInO alloy thin films

Indium zinc oxide (IZO) thin films with different percentages of In content (In/[In+Zn]) are synthesized on glass substrates by magnetron sputtering, and the structural, electrical and optical properties of IZO thin films deposited at different In₂O₃ target powers are investigated. IZO thin films grown at different In₂O₃ target sputtering powers show evident morphological variation and different grain sizes. As the In₂O₃ sputtering power rises, the grain size becomes larger and electrical mobility increases. The film grown with an In₂O₃ target power of 100 W displays the highest electrical mobility of 13.5 cm·V^-1·s^-1 and the lowest resistivity of 2.4 × 10^-3 Ω·cm. The average optical transmittance of the IZO thin film in the visible region reaches 80% and the band gap broadens with the increase of In₂O₃ target power, which is attributed to the increase in carrier concentration and is in accordance with Burstein-Moss shift theory.