Rare Mononuclear Lithium–Carbene Complex for Atomic Layer Deposition of Lithium Containing Thin Films

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Jorit Obenlüneschloß - , Ruhr University Bochum (Author)
  • Nils Boysen - , Fraunhofer Institute for Microelectronic Circuits and Systems (Author)
  • Karl Rönnby - , University College Cork (Author)
  • Arbresha Muriqi - , University College Cork (Author)
  • Volker Hoffmann - , Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • Carlos Abad - , Federal Institute for Materials Research and Testing Berlin (Author)
  • Detlef Rogalla - , Ruhr University Bochum (Author)
  • Ulrike Brokmann - , Ilmenau University of Technology (Author)
  • Edda Rädlein - , Ilmenau University of Technology (Author)
  • Michael Nolan - , University College Cork (Author)
  • Anjana Devi - , Chair of Materials Chemistry (gB/IFW), Ruhr University Bochum, Fraunhofer Institute for Microelectronic Circuits and Systems, Leibniz Institute for Solid State and Materials Research Dresden (Author)

Abstract

Lithium is the core material of modern battery technologies and fabricating the lithium-containing materials with atomic layer deposition (ALD) confers significant benefits in control of film composition and thickness. In this work, a new mononuclear N-heterocyclic carbene (NHC) stabilized lithium complex, [Li(tBuNHC)(hmds)], is introduced as a promising precursor for ALD of lithium-containing thin films. Structural characterization is performed, comparing density functional theory (DFT) and single-crystal X-ray diffraction (SC-XRD), confirming a rare mononuclear structure. Favorable thermal properties for ALD applications are evidenced by thermogravimetric analysis (TGA). The compound exhibits a low melting point, clean evaporation, and its volatility parameters are encouraging compared to other lithium precursors. ALD trials using [Li(tBuNHC)(hmds)] with ozone demonstrate its effectiveness in depositing LiSixOy films. The ALD process exhibits a saturated growth per cycle (GPC) of 0.95 Å. Compositional analysis using Rutherford backscattering spectrometry/nuclear reaction analysis (RBS/NRA), X-ray photoelectron spectrometry (XPS), and glow discharge optical emission spectrometry (GD-OES), confirms the presence of lithium and silicon in the expected ratios. This work not only presents a new ALD precursor but also contributes to the understanding of lithium chemistry, offering insights into the intriguing coordination chemistry and thermal behavior of lithium complexes stabilized by NHC ligands.

Details

Original languageEnglish
Article numbere202513066
JournalAngewandte Chemie - International Edition
Volume64
Issue number47
Publication statusPublished - 17 Nov 2025
Peer-reviewedYes

External IDs

PubMed 40908744

Keywords

ASJC Scopus subject areas

Keywords

  • Atomic layer deposition, Carbene ligands, Lithium, Precursor, Silicate