Atomic Layer Deposition of Hafnium(IV) Oxide on Graphene Oxide: Probing Interfacial Chemistry and Nucleation by using X-ray Absorption and Photoelectron Spectroscopies

Theodore E G Alivio; Luis R De Jesus; Robert V Dennis; Ye Jia; Cherno Jaye; Daniel A Fischer; Uttam Singisetti; Sarbajit Banerjee

doi:10.1002/cphc.201500434

Atomic Layer Deposition of Hafnium(IV) Oxide on Graphene Oxide: Probing Interfacial Chemistry and Nucleation by using X-ray Absorption and Photoelectron Spectroscopies

Chemphyschem. 2015 Sep 14;16(13):2842-2848. doi: 10.1002/cphc.201500434. Epub 2015 Jul 27.

Authors

Theodore E G Alivio^{1

2}, Luis R De Jesus^{1

2}, Robert V Dennis^{1

2}, Ye Jia³, Cherno Jaye⁴, Daniel A Fischer⁴, Uttam Singisetti³, Sarbajit Banerjee^{1

2}

Affiliations

¹ Department of Chemistry, Texas A&M University, College Station, Texas 77842-3012 (USA).
² Department of Materials Science and Engineering, Texas A&M University, College Station, Texas 77843-3003 (USA).
³ Department of Electrical Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260-3000 (USA).
⁴ Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (USA).

PMID: 26227822
DOI: 10.1002/cphc.201500434

Abstract

Interfacing graphene with metal oxides is of considerable technological importance for modulating carrier density through electrostatic gating as well as for the design of earth-abundant electrocatalysts. Herein, we probe the early stages of the atomic layer deposition (ALD) of HfO₂ on graphene oxide using a combination of C and O K-edge near-edge X-ray absorption fine structure spectroscopies and X-ray photoelectron spectroscopy. Dosing with water is observed to promote defunctionalization of graphene oxide as a result of the reaction between water and hydroxyl/epoxide species, which yields carbonyl groups that further react with migratory epoxide species to release CO₂ . The carboxylates formed by the reaction of carbonyl and epoxide species facilitate binding of Hf precursors to graphene oxide surfaces. The ALD process is accompanied by recovery of the π-conjugated framework of graphene. The delineation of binding modes provides a means to rationally assemble 2D heterostructures.

Keywords: NEXAFS; XPS; atomic layer deposition; graphene oxide; hafnium(IV) oxide.