A cobalt(II) heteroarylalkenolate precursor for homogeneous Co3O4 coatings by atomic layer deposition

We present a new and efficient cobalt precursor, Co-II(DMOCHCOCF3)(2), to prepare Co3O4 thin films and conformal coatings. In the synthesis of this Co complex, heteroaryl moieties and CF3-groups were combined leading to the precursor with high thermal stability and volatility. The suitability of this precursor for ALD deposition was tested on flat silicon substrates and TiO2/C nanofibers upon process optimization. Deposition at 200 degrees C results in homogeneous and smooth Co3O4 thin films with a growth rate of 0.02 nm per cycle. Conformal coatings have been successfully obtained on TiO2/C nanofibers, making them an attractive platform for surface chemistry studies on high aspect ratio structures for future photo-catalysts, sensors, supercapacitors and batteries.