Electrical properties of In2O3 and ITO thin films formed by solution process using In(acac)3 precursors

Abstract

Indium oxide (In2O3) and indium tin oxide (ITO) films were prepared by the solution process using an indium acetylacetonate [In(acac)3] precursor, and their electrical properties were also characterized. Rapid thermal annealing (RTA) of In2O3 and ITO precursor-gel films was performed in O2 by varying the annealing temperature and time. The obtained Hall mobility of In2O3 films is as high as 42.7 cm2 V−1 s−1, while resistivity as low as 2.5 × 10−3 Ωcm is obtained for 1 wt% ITO with a Hall mobility and a carrier concentration of 24.1 cm2 V−1 s−1 and 1.0 × 1020 cm−3, respectively. The ITO was prepared using two different Sn precursors—one was SnCl2 and the other was Sn(acac)2—to compare its electrical properties—and it was found that the Hall mobility was higher in the ITO prepared using Sn(acac)2 as the Sn precursor. Using the solution-processed In2O3 as a channel, a thin film transistor was also fabricated and n-channel transistor operation was confirmed.