3 (Fig. ). As the coordination sphere of the metal centre is all In-N bonds, their use for In2O3 is especially attractive as it makes formation of In-O bonds thermodynamically favourable. This would allow H2O to be used as the co-reactant and remove the need for strong oxidants such as O3 and O2 plasma. Precursors 1-3 have been used with H2O for thermal ALD of In2O3 with all showing self-limiting growth behaviour. Although all precursors gave similar growth rates of In2O3 (0.45-0.55 Å/cycle), 1 was found to have faster kinetics with the surface and H2O than 2 and 3. A surface chemical model was used to explain the faster kinetics of 1, which was thought to be due to its smaller endocyclic carbon substituent. This allowed the exocyclic N-isopropyl groups of the ligand to fold up more, leading to a surface species with less surface repulsion and a more exposed In centre for its subsequent reaction with H2O. This surface chemical model was further confirmed when we used 1-3 for plasma ALD of InN. Again, 1 was found to be superior to 2 and 3. To continue this trend, we replaced the substituted endocyclic carbon to a nitrogen atom. This led to our discovery of the indium(III) triazenide (4) (Fig. ), which we used with NH3 plasma to render high-quality InN. 38 Here, we investigate the use of 4 as In precursor in thermal ALD of In2O3 with water as oxidant. The ALD characteristics, optical and electrical properties of the deposited In2O3 films are investigated and a direct comparison between 4 and 1 is done.