Materials Chemistry

High-performance iridium thin films for water splitting by CVD using new Ir(I) precursors



Thin films of iridium can be utilized in a wide range of applications and are particularly interesting for catalytic transformations. For the scalable deposition of functional Ir thin films, metal-organic chemical vapor deposition (MOCVD) is the method of choice, for which organometallic precursors that embody a high volatility and thermal stability need to be specifically tailored. Herein, we report the synthesis, analysis, and evaluation of new volatile Ir(I)-1,5-cyclooctadiene complexes bearing all-nitrogen coordinating guanidinate (DPDMG), amidinate (DPAMD) and formamidinate (DPfAMD) ligands. The amidinate-based Ir complex [Ir(COD)(DPAMD)] together with O2 was implemented in MOCVD experiments resulting in highly crystalline, dense, and conductive Ir films on a variety of substrate materials. The Ir deposits achieved an outstanding electrochemical performance with overpotentials in the range of 50 mV at –10 mA‧cm-2 for catalytic hydrogen evolution reaction (HER) in acidic solution. The ability to deposit Ir layers via MOCVD exhibiting promising functional properties is a significant step towards large scale applications.


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Supplementary material

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Supporting Information for Manuscript
More details and information on analysis of the precursors and analysis of the thin films by various methods.