Atomic/molecular Layer Deposition Mechanism of Alucone Organic–inorganic Hybrid Materials

The atomic/molecular layer deposition (ALD/MLD) technique has been used to prepare various organ-ic-inorganic hybrid materials, namely metalcones, such as lithicone, alucone, titanicone, hafnicone and vana-dicone. These metalcones have been applied in the fields of microelectronics, energy and catalysis. In this work, the ALD/MLD mechanism of alucone was explored using density functional theory calculations. The results show that trimethylaluminum (TMA) can be easily adsorbed and dissociated on the hydroxylated SiO2 surface. Three organic precursors, ethylene glycol (EG), ethylenediamine (EDA) and oxalic acid (OX) can react with the methylated surface through four-membered ring (4MR) and six-membered ring (6MR) pathways. The 6MR mode is favorable and can reduce the reaction barriers. The reactivity order is EG > OX > EDA. In the complementary reaction of alucone ALD/MLD, the reactivity order of TMA on EG-hydroxylated, EDA-aminated and OX-carboxylated surfaces is also in accordance with that of EG, EDA and OX on the methylated surfaces. These insights into the ALD/MLD mechanism of alucone can provide theoretical guidance for ALD/MLD design and growth of metalcone organic-inorganic hybrid materials.