Subvalent Iridium Precursors for Atom-Efficient Chemical Vapor Deposition of Ir and IrO₂ Thin Films

Abstract

A new heteroleptic Ir(I) compound exhibiting high volatility and defined thermal decomposition under CVD conditions is reported. The new iridium precursor [(COD)Ir(ThTFP)] (COD = cyclooctadiene, ThTFP = (Z)-3,3,3-trifluoro-1-(thiazol-2-yl)prop-1-en-2-olate) unifies both reactivity and sufficient stability through its heteroleptic constitution to provide a precise control over compositional purity in CVD deposits. The solution integrity of the monomeric Ir(I) complex was investigated by 1D and 2D NMR spectroscopy and EI mass spectrometry, whereas the molecular structure was confirmed by single-crystal diffraction. CVD experiments demonstrated the suitability of the iridium compound for an atom-efficient (high molecule-to-precursor yield) gas-phase deposition of nanocrystalline iridium films that could be converted into crystalline iridium dioxide upon heat treatment to demonstrate their electrocatalytic potential in the oxygen evolution reaction.

Efficient and Selective Methane Borylation Through Pore Size Tuning of Hybrid Porous Organic‐Polymer‐Based Iridium Catalysts

“…For example, CAL‐1‐Ir (Figure a and Figure S1), like most of the well‐defined polycarbazoles reported previously, has three different signal peaks between 100 and 150 ppm, indicating the presence of an aromatic carbon atom linked with a nitrogen atom (148 or 143 ppm), a carbon atom linked with a hydrogen atom (110 ppm), and a carbon atom linked with other atoms (127 or 128 ppm). In addition, two new signal peaks were found in CAL‐1‐Ir at 67 and 29 ppm, which indicate the presence of methylene carbon derived from COD groups . A similar 13 C NMR signal distribution was found for other copolymers and is shown in Figure S2.…”

High-temperature X-ray scattering studies of atomic layer deposited IrO2

“…Anodization of an Ir film (Cogan, 2008) and thermal oxidation of metallic iridium (Bayer & Wiedemann, 1975;Chalamala et al, 1999Chalamala et al, , 2000 have been in use for a long period of time. Furthermore, IrO 2 thin films are also deposited hydrothermally (da Silva et al, 2017) using the Adams fusion method (Rasten et al, 2003;Abbott et al, 2016), spray pyrolysis (Patil et al, 2003), electro-deposition (Yagi et al, 2005), sol-gel methods (Bernicke et al, 2015), pulsed-laser deposition (Gong et al, 2009;Hou et al, 2017), laser ablation (Wang et al, 2006;Gong et al, 2013), chemical vapour deposition (CVD) (Liao et al, 2001;Ju ¨rgensen et al, 2017) and atomic layer deposition (ALD) (Ha ¨ma ¨la ¨inen et al, 2008(Ha ¨ma ¨la ¨inen et al, , 2014. Among the various thin-film deposition methods, ALD offers unsurpassed conformality and thickness uniformity properties, making it the method of choice for coating highly complex shapes (Ritala & Niinisto ¨, 2009;George, 2010;Leskela ¨et al, 2014).…”

Volatile Rhenium(I) Compounds with Re–N Bonds and Their Conversion into Oriented Rhenium Nitride Films by Magnetic Field-Assisted Vapor Phase Deposition

“…However, due to the lack of suitable nitrogen sources, multisource CVD of phase-pure rhenium nitride layers is rather challenging . For instance, Re­(I) complexes with nitrogen-rich multidentate ligands, − which saturate the coordination sphere of the metal center and exhibit predetermined breaking points, are attractive alternative for low-temperature methods such as CVD and ALD techniques. Due to the soft character of the Re­(I) central atom, the incorporation of harder donor atoms like oxygen and carbon is suppressed, and phase contamination is reduced.…”