Naslov
Mechanistic Insight into Solution-Based Atomic Layer Deposition of CuSCN Provided by In Situ and Ex Situ Methods

Autori
Hilpert, Felix ; Liao, Pei-Chun ; Franz, Evanie ; Koch, Vanessa M. ; Fromm, Lukas ; Topraksal, Ece ; Görling, Andreas ; Smith, Ana-Sunc̆ana ; Barr, Maïssa K. S. ; Bachmann, Julien ; Brummel, Olaf ; Libuda, Jörg

Izvornik
ACS applied materials & interfaces (1944-8244) 15 (2023), 15; 19536-19544

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
solution atomic layer deposition ; liquid phase ; in situ IR spectroscopy ; atomic force microscopy ; copper thiocyanate ; neural network ; density functional theory ; liquid atomic layer deposition

Sažetak
Solution-based atomic layer deposition (sALD) processes enable the preparation of thin films on nanostructured surfaces while controlling the film thickness down to a monolayer and preserving the homogeneity of the film. In sALD, a similar operation principle as in gas-phase ALD is used, however, with a broader range of accessible materials and without requiring expensive vacuum equipment. In this work, a sALD process was developed to prepare CuSCN on a Si substrate using the precursors CuOAc and LiSCN. The film growth was studied by ex situ atomic force microscopy (AFM), analyzed by a neural network (NN) approach, ellipsometry, and a newly developed in situ infrared (IR) spectroscopy experiment in combination with density functional theory (DFT). In the self-limiting sALD process, CuSCN grows on top of an initially formed two-dimensional (2D) layer as three-dimensional spherical nanoparticles with an average size of ∼25 nm and a narrow particle size distribution. With increasing cycle number, the particle density increases and larger particles form via Ostwald ripening and coalescence. The film grows preferentially in the β-CuSCN phase. Additionally, a small fraction of the α-CuSCN phase and defect sites form.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

Napomena
The Supporting Information is available free of
charge at
https://pubs.acs.org/doi/10.1021/acsami.2c16943.

In situ IR spectra between 3000 and 1100 cm–1
of the growth of CuSCN by sALD; comparison of AFM
images of the growth of CuSCN by sALD with the
corresponding blind experiments; ν(SCN) band
position of ν-CuSCN during 23 cycles of the sALD
process; detailed measurement procedure and
proposed reaction mechanism for deposition of
CuSCN; description of home-build in situ sALD flow
cell; and proof of self-limitation of the
deposition process (PDF)

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