Atomic/molecular layer deposition: a direct gas-phase route to crystalline metal–organic framework thin films

Abstract

Atomic/molecular layer deposition offers us an elegant way of fabricating crystalline copper(ii)terephthalate metal-organic framework (MOF) thin films on various substrate surfaces. The films are grown from two gaseous precursors with a digital atomic/molecular level control for the film thickness under relatively mild conditions in a simple and fast one-step process.

ALD/MLD processes for Mn and Co based hybrid thin films

“…4 Most of the early ALD/MLD works concern very few metal constituents (mainly Al, Zn, Ti and Zr) 1,4,[7][8][9][10][11][12][13] but in the most recent works the technique has been successfully extended to some 3d, 4f and alkali metal based hybrid thin films with interesting luminescence and electrochemical properties. [14][15][16][17] Hybrid thinfilm materials based on 3d transition elements with partiallyfilled d orbitals would be attractive due to their potential to show e.g. exciting electrical, magnetic and catalytic properties; in particular, based on the experiences from conventional inorganic compounds, manganese and cobalt would be among the most interesting 3d metal constituents.…”

In Situ Atomic/Molecular Layer-by-Layer Deposition of Inorganic–Organic Coordination Network Thin Films from Gaseous Precursors

“…21 We obtained very recently positive evidence that it is possible to find ALD/MLD fabrication conditions for the in-situ deposition of crystalline metal-organic thin films; our proof-of-theconcept data were for Li-TP and Cu-TP thin films (TP stands for terephthalate). 20,22 Here we introduce a straightforward and readily reproducible ALD/MLD process for the manufacturing of calcium terephthalate (Ca-TP) coordination network thin films from Ca(thd)2 and benzene-1,4-dicarboxylic acid or so-called terephthalic acid (TPA) precursors over a notably wide deposition temperature range; schematics of our ALD/MLD process are shown in Figure 1. Calcium-terephthalate networks have been synthesized in bulk form and demonstrated to be interesting candidates for example for Li-ion battery anode materials; 23 also known is that the Ca-TP materials synthetized in bulk form tend to have DMF and/or H2O molecules in their structures, and thus require high-temperature annealing to obtain the solvent-free product.…”

“…The strongly emerging atomic/molecular layer deposition (ALD/MLD) technique where ALD cycles for inorganic constituents are combined with MLD cycles for organic constituents would in principle be an elegant way of fabricating inorganic-organic coordination network thin films; [18][19][20] it provides us with a simple direct route to build up hybrid metal-organic materials with an atomic/molecular level accuracy for the film thickness and composition even over structurally challenging substrates, as it relies on sequential self-saturated gas-to-surface reactions achieved by pulsing of the precursor materials separately after each time purging the reactor chamber with inert gas. The grand challenge in ALD/MLD has been that the metal-organic hybrid thin films fabricated by the technique have been amorphous even after ordinary post-deposition heat treatments; 18 only a two-step post-deposition annealing treatment under strictly humidity-controlled conditions was shown to yield crystalline coordination network structures.…”

ALD/MLD fabrication of luminescent Eu-organic hybrid thin films using different aromatic carboxylic acid components with N and O donors

“…The strongly emerging atomic/molecular layer deposition (ALD/MLD) thinfilm technique [8][9][10][11][12] based on sequential gas-surface reactions of gaseous inorganic and organic precursors would be ultimately suited to fabricate such state-of-the-art hybrid materials. There is a strive to extend the technique to a wider range of metal and organic backbone constituents, [13][14][15] and recently we indeed presented a highly viable ALD/MLD process based on Eu(thd)3 and 3,5-pyridinedicarboxylic acid (3,5-PDC) precursors to fabricate Eu-based inorganic-organic hybrid thin films with attractive photoluminescence properties. 16 Here upon the film growth Eu(thd)3 reacts through ligand-exchange reactions with 3,5-PDC to form Eu-PDC films in an atomic/molecular layer-bylayer manner.…”