Synthesis of undoped and Ni doped InTaO4 photoactive thin films by metal organic chemical vapor deposition

Abstract Indium tantalate (InTaO 4 ) and nickel doped InTaO 4 , In 1 −  x Ni x TaO 4 ( x  = 0.1), thin films were grown by Pulsed Injection Metal Organic Chemical Vapor Deposition (PI-MOCVD). The deposition was carried out using as precursors a solution of Ta(OC 2 H 5 ) 5 and In(THD) 3 in toluene for the InTaO 4 and Ta(OC 2 H 5 ) 5 , In(THD) 3 and Ni(THD) 2 in toluene for the In 1 −  x Ni x TaO 4 thin films. The compounds formation, films stoichiometry and crystalline structure were studied as a function of substrate temperature and precursors concentration. Crystalline and stoichiometric (indium/tantalum atomic ratio of 1) films were obtained under optimized deposition conditions. Post-deposition heat treatment in N 2 or O 2 atmospheres further improved the crystalline quality of the films. Under optimum growth conditions the films showed no phase segregations, a feature that makes them suitable for future photocatalytic applications. The study of hydrophilic activities of In 1 −  x Ni x TaO 4 thin films evidenced a decrease of the water contact angle up to 60° under visible light irradiation and a complete transformation in a superhydrophilic state upon UV irradiation.