Heteroleptic Tin(IV) Aminoalkoxides and Aminofluoroalkoxides as MOCVD Precursors for Undoped and F-Doped SnO₂ Thin Films

Abstract

A series of asymmetric and potentially bidentate amino alcohols and amino fluoro alcohols (RNOH) having a different number of methyl/trifluoromethyl substituents at the α-carbon atom, [HOC­(R1)­(R2)­CH2NMe2] (R1 = R2 = H (dmaeH); R1 = H, R2 = CH3 (dmapH); R1 = R2 = CH3 (dmampH); R1 = H, R2 = CF3 (F-dmapH); R1 = R2 = CF3 (F-dmampH)) have been used to develop new monomeric and heteroleptic tin­(IV) amino­(fluoro)­alkoxides [Sn­(OR)2(ORN)2] (R = Et, Pr i , Bu t ). These new complexes, which were thoroughly characterized by spectroscopy (IR and multinuclei NMR (1H, 13C, 19F, and 119Sn)) as well as single-crystal X-ray studies on representative samples, were investigated for their thermal behavior to determine their suitability as MOCVD precursors for the deposition of metal oxide thin films. The two most suitable compounds, [Sn­(OBu t )2(dmamp)2] and [Sn­(OBu t )2(F-dmamp)2], were used in a direct liquid injection chemical vapor deposition (DLI-CVD) process to deposit undoped SnO2 and F-doped SnO2 thin films, respectively, on silicon and quartz substrates. Film growth rates at different temperatures (from 400 to 700 °C), film thickness, crystalline quality, and surface morphology were investigated. The films deposited on quartz showed high transparency (above 80%) in the visible region and low carbon contamination on the surface (11–13% from XPS), which could easily be removed completely with 2 min of Ar+ sputtering.

Evaluation of Sn(ii) aminoalkoxide precursors for atomic layer deposition of SnO thin films

“…The resonances ascribed to the {CH 2 } and {CMe 2 } moieties appear to be coincidental in the 13 C NMR spectrum, with the tertiary environment appearing more downfield ( = 72.80 ppm) than the methylene ( = 72.19 ppm), in contrast to compounds 1a and 1b, in which the alkoxide carbon environment is found further upfield of the methylene group. The 1 H, 13 C, and 19 F NMR spectra for 1d at room temperature display a pattern of resonances consistent with a highly…”

“…Recently, identical ligands have been exploited in the development of heteroleptic Sn(IV) alkoxide/aminoalkoxide complexes for SnO 2 and F-doped-SnO 2 by MOCVD. 19 The incorporation of Lewis basic donor groups into alkoxide ligands, and their subsequent application as volatile MOCVD precursors, was pioneered by Herrmann with the development of a series of ether and amine functionalised alcohols. 20 Sequential substitution of alkyl groups on the -carbon atom in the functionalised alkoxide ligand has been shown to favour chelation over potential bridging modes.…”

Designed sol–gel precursors for atomically dispersed Nb and Pb within TiO2 as catalysts for dihydroxyacetone transformation

“…For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/d0dt03726e perties of the final material produced have prompted us to investigate the designed metal aminoalkoxides for the solution-and vapor-phase synthesis of metal oxides. [15][16][17][18][19][20] By extending the above studies, we report here the synthesis, structural characterization and hydrolytic behavior of new N-methyldiethanolamine-modified precursors of titanium(IV), niobium(V) and lead(II). The choice of these metals was motivated by the aim to synthesize water-tolerant TiO 2 nanoparticles doped with Nb or Pb, dispersed homogeneously and at the atomic scale within the TiO 2 matrix to tune its catalytic acidbase properties.…”

“…but also, due to their action as surfactants, stabilize the colloidal solutions obtained during hydrolysis. 15 In this regard, we have shown previously that aminoalcohols are not only easily modified to modulate their steric and electronic properties, 16 but their metal derivatives are very attractive sol-gel precursors for metal oxide nanomaterials because of the favorable hydrolysis and condensation characteristics and their transformation into oxides at relatively low temperatures. [17][18][19][20] These characteristics and the interesting structural features that play a role in determining the pro-Scheme 1 Dihydroxyacetone conversion to lactic acid via pyrulvaldehyde formation.…”

Tin dioxide-based nanomaterials as anodes for lithium-ion batteries

“…281,283 Apart from doped-graphene, atom-doped SnO 2 , such as uorine-doped tin oxide 138 and antimony-doped tin oxide 122 can also be used with pristine graphene as an anode material. [284][285][286][287] For example, Xu et al has successfully fabricated composites of uorine-doped tin oxide (FTO) and rGO from a colloidal solution containing FTO nanocrystals and rGO by a hydrothermal treatment; the FTO nanocrystals were tightly embedded in the RGO nanosheets. As an anode material, the FTO/RGO composite showed high structural stability during the lithiation and delithiation processes.…”