Facile synthesis of an organic/inorganic hybrid 2D structure tincone film by molecular layer deposition.

Organic/inorganic hybrid tincone films were deposited by molecular layer deposition (MLD) using N,N'-tert-butyl-1,1-dimethylethylenediamine stannylene(II) as a precursor and hydroquinone (HQ) as an organic reactant. From previous studies it is known that SnO can be fabricated through a reaction with H2O, which has low oxidizing power. Similarly, when combined with HQ having a bi-functional hydroxyl group, SnO-based 2D hybrid tincones can be produced. In most aromatic ring-based metalcones described in previous studies, graphitization by pyrolysis occurred during post-annealing. In this study of tincones fabricated with a divalent precursor after a vacuum post-annealing process, the structural rearrangement of the SnO and the benzene ring bonds proceeded to form a SnO-based hybrid 2D structure. The rearrangement of the resulting structure occurred through π-π stacking (without pyrolysis) of the benzene ring. To understand the mechanism of fabrication of 2D hybrid tincones by π-π stacking of the benzene ring and the increase of the crystallinity of SnO after the annealing process, the structural rearrangement was observed using X-ray photoelectron spectroscopy (XPS), grazing incidence X-ray diffraction (GIXRD), grazing-incidence wide-angle X-ray scattering (GIWAXS), and Raman spectroscopy. Thereafter, the design of the crystal structure was investigated.