The first example of polymeric lanthanide tetrakis-trifluoroacetates in chemical solution deposition of up-converting NaGdF4:Yb,Er,Nd thin films

Abstract

A series of lanthanide tetrakis-trifluoroacetates {(detaH₂)₂[La₂(tfa)₈]₂(CH₃CN)₅(H₂O)₂}_n and (detaH₂)_n[Ln(tfa)₄]_2n (Ln = Pr–Eu), mixed-ligand complexes [La(tfa)₃(CH₃CN)(H₂O)]_n, [Gd(tfa)₃(deta)₂](ⁱPrOH) and [Yb(tfa)₂(deta)₂](tfa), as well as detaH₂(tfa)₂ were isolated and characterized. All lanthanide tetrakis-trifluoroacetates contain two types of 1D anionic chains [Ln(tfa)₄]_nⁿ⁻ and cavities occupied by detaH₂²⁺ cations and solvating H₂O and CH₃CN molecules. The thermal behavior of (detaH₂)_n[Ln(tfa)₄]_2n in air is investigated by TGA, in situ VT-PXRD and total X-ray scattering with PDF analysis, and the formation of metal fluorides occurs upon heating to 300 °C. The application of solution with lanthanide trifluoroacetates and diethylenetriamine (deta) as precursors for chemical deposition of β-NaGdF₄:Er,Yb,Nd thin films is reported. The deposited β-NaGdF₄:Er,Yb,Nd thin film demonstrates up-conversion luminescence under 980 and 808 nm laser excitation.