Indium-tin-oxide thin films prepared by dip-coating of indium diacetate monohydroxide and tin dichloride

Tin-doped In2O3 (ITO) films were prepared by the dip-coating method using a n ethanol solution of indium diacetate monohydroxide, In(OH)(CH3COO)(2), an d tin dichloride. SnCl2. 2H(2)O, with 2-aminoethanol (monoethanolamine), H2 NC2H4OH. The influence of the tin concentration was investigated between 0 and 20 at.% Sn. The composition of the films (thickness similar to 90 nm) a pproximately agreed with that of the solution when the dipping and the heat ing at 600 degreesC in air for 30 min were repeated three times. The lattic e constant of the ITO films increased by the tin addition and annealing at 600 degreesC for 1 h in a nitrogen flow. The films were highly transparent in the visible range. At 6.4 at.% Sn, the maximum carrier concentration (6. 2 X 10(20) cm(-3)) and minimum resistivity (5.8 X 10(-4) Omega cm) were obt ained after annealing in nitrogen (oxygen partial pressure similar to 2.0 P a). The mobilities of the ITO films (similar to 10 cm(2) V-1 s(-1)) were al most independent of the film composition and the annealing, The mobilities of the undoped In2O3 films were similar to 40 cm(2) V-1 s(-1). (C) 2001 Pub lished by Elsevier Science B.V. All rights reserved.