Indium oxide (In2O3) is a material of high interest due to its high electrical conductivity and optical transparency, making it a key material for transparent and optoelectronics 1 e.g. microelectronic displays on touch screens. The electrical conductivity of In2O3 2 is controlled by the stoichiometry of the film and is typically enhanced by substituting the In atoms with 5-10 atomic % Sn . All applications of In2O3 as transparent conducting layers require the deposition of high-quality thin films of In2O3. This requirement is the driving force for extensive studies by sputtering , thermal evaporation , chemical vapor deposition , and atomic layer deposition (ALD) . ALD of In2O3 is especially interesting as it can deposit high quality films with precise thickness, controlled composition, low impurity contents, and excellent conformality on complex substrates has been demonstrated. ALD of In2O3 was first reported using InCl3 and either H2O or H2O2 at temperatures between 300-500 °C. The low vapor pressure of InCl3, the generation of HCl as the reaction by-product and the possibility for InCl3 to etch the growing In2O3 layer has motivated the use of other In precursors. Furthermore, there has been limitations on availability of efficient indium precursors that give processes with high growth rates, fully self-limiting reactions, low impurity contents and good film crystallinity. The indium compounds tested as precursors in combination with different oxidants, within different deposition temperature windows are shown in Table .