Atomic/Molecular Layer Deposition of s‐Block Metal Carboxylate Coordination Network Thin Films

Abstract

We present novel atomic/molecular layer deposition (ALD/MLD) processes for the fabrication of crystalline inorganic-organic coordination network thin films with different s-block elements. Terephthalic acid is employed as the organic precursor. Such thin films could enable for example, next-generation battery, sensor and gas-storage technologies. The deposition processes fulfill the basic principles of ALD/MLD-type growth including the sequential self-saturated gas-surface reactions and atomic/molecular-level control for the film thickness, and yield crystalline thin films in a wide deposition temperature range. Structural characterization of the films is performed by grazing incidence X-ray diffraction (GIXRD) and Fourier-transform infrared (FTIR) spectroscopy. The data do not unambiguously prove but also do not rule out the crystal structures previously reported for the corresponding bulk samples. We moreover demonstrate the growth of crystalline thin films of a new terephthalate material with La as the metal component. Upon humidity treatments the Li, Na, K, Ba, and La terephthalate films remain unaffected while the Mg, Ca, and Sr terephthalate films reversibly absorb water molecules forming well-defined crystalline water-derivative phases.

New s‐Block Metal Pyridinedicarboxylate Network Structures through Gas‐Phase Thin‐Film Synthesis

“… Summary of the s‐block metal 3,5‐PDC films realized in this study, and the corresponding TPA thin films reported earlier: crystalline films are indicated in green and amorphous films in striped gray. We also give the density values (in g cm −3 ) determined for each thin‐film sample from the critical angle value in the XRR pattern.…”

“…The GPC values were calculated from the X‐ray reflectivity (XRR)‐determined film thickness values; an example of a typical XRR curve is shown in the inset of Figure c. From Figure b it can be seen that the GPC value is well saturated when the Mg(thd) 2 pulse length is 5 s (subsequent N 2 purge length 5 s) and the 3,5‐PDC precursor pulse length is 15 s (subsequent N 2 purge length 30 s). It should be mentioned that very similar pulse length values are typically used for many other organic precursors in ALD/MLD processes . We then fixed these pulse/purge lengths for the rest of the experiments.…”

“…New ALD/MLD processes have been actively developed for a decade, but up until a few years ago it seemed that the technique was only capable to yield amorphous metal–organic thin films . Initially, efforts were made to apply different post‐deposition treatments to crystallize CP‐type metal–organic structures from amorphous as‐deposited films, but three years ago we succeeded in growing the first in situ crystalline ALD/MLD metal–organic thin films . In particular and most relevant to the present work, we recently fabricated a series of crystalline s‐block metal‐based terephthalate thin films with “sheet‐like” ordered structures through ALD/MLD, and investigated their water‐intercalation characteristics .…”

“…[29,30] Initially,e fforts were made to apply different post-deposition treatments to crystallize CP-type metal-organic structures from amorphous as-deposited films, [33][34][35] but three years ago we succeeded in growing the first in situ crystalline ALD/MLD metal-organic thin films. [36][37][38][39][40][41][42][43][44] In particular and most relevantt ot he present work, we recently fabricated a series of crystalline s-block metal-based terephthalate thin films with "sheet-like" ordered structures through ALD/MLD, and investigated their water-intercalation characteristics. [36,38,41,42] Now in the presentw ork, we challenge for the first time s-blockm etal-PDC materials with the anticipation to discover novel CP-types tructures.…”

Atomic/Molecular Layer Deposited Iron–Azobenzene Framework Thin Films for Stimuli‐Induced Gas Molecule Capture/Release

“…[25] In ALD/MLD the metal-organic material is grown from two mutually reactive gaseous precursors sequentially pulsed into the reactor chamber with an intermediate inert-gas purging step.L ike in the case of the parent ALD (atomic layer deposition) technology for simple inorganic materials,t his results in self-limited gas-surface reactions and consequently in the atomic/molecular level control of the growing thin-film material on the chosen substrate surface. [28][29][30][31] Herein we report the ALD/MLD growth of crystalline iron-azobenzene thin films in which the azobenzene moieties are an integral part of the crystal framework. [28][29][30][31] Herein we report the ALD/MLD growth of crystalline iron-azobenzene thin films in which the azobenzene moieties are an integral part of the crystal framework.…”