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Significant work has recently focused on developing novel materials suitable for solar technologies with better conversion efficiencies, while maintaining low costs. BaF2 has been investigated as a fluoride host for doping with luminescent ions for energy conversion processes in photovoltaic cells. This work employed a metal–organic chemical vapor deposition technique to prepare nanostructured europium-doped BaF2 thin films on silicon and quartz substrates. Samples have been fabricated by varying the deposition temperature from 300 to 600 °C in order to examine how temperature affects the structure, morphology, and luminescence of Eu-doped BaF2 thin films. A multicomponent combination of fluorinated β-diketonate metal–organic precursors of barium and europium, Ba(hfa)2·tetraglyme and Eu(hfa)3·diglyme, in an appropriate molar ratio, is employed to fabricate BaF2 based thin films. These precursors serve as a single molten source by delivering all the elements required (Ba, Eu, and F) for forming the Eu-doped BaF2 phase due to the similar nature of the ligands. On silicon substrates, preliminary deposition tests have been carried out to confirm the purity, homogeneity, and appropriate stoichiometry of films. The obtained results pave the way for the production of BaF2 thin films doped with lanthanide ions, particularly interesting for their up-conversion (UC), down-conversion (DC), and down-shifting (DS) properties. [ABSTRACT FROM AUTHOR]

Atmospheric pressure (AP) vapor phase processes such as spatial atomic layer deposition (S-ALD) and AP-metalorganic chemical vapor deposition (AP-MOCVD) are becoming increasingly appealing for their use in a variety of academic and industrial applications. Evaluation of precursor vapour pressures is crucial for their application in AP processes and to this aim the Langmuir equation has been applied as a simple and straightforward method for estimating the vapor pressure and vaporization enthalpy of various metalorganic precursors. Using benzoic acid as a calibration reference, the vapour pressure-temperature curves for several alkaline-earth β-diketonate fluorinated compounds, with molecular formula "M(hfa) 2 ·L" (with M = Mg, Ca, Sr, Ba; Hhfa = 1,1,1,5,5,5-hexafluoroacetylacetone and L = diglyme, triglyme, and tetraglyme) are derived from their termogravimetric curves. Thus, the enthalpy of vaporization of all complexes has been estimated using the Clausius-Clapeyron equation. As a proof of concept, preliminary results on the use of [Mg(hfa) 2 ·2H 2 O]·2diglyme and [Ca(hfa) 2 ·diglyme·H 2 O] or [Ca(hfa) 2 ·triglyme] as precursors for AP-MOCVD deposition of MgF 2 and CaF 2 in the form of thin films are presented. This approach may be used to easily determine vapor pressures of complexes and thus evaluate " a priori " the suitability of a compound as precursor for AP-MOCVD and/or spatial ALD.