Fluoride Doping in Crystalline and Amorphous Indium Oxide Semiconductors

Aritra Sil, Michael J. Deck, Elise A. Goldfine, Chi Zhang, Sawankumar V. Patel, Steven Flynn, Haoyu Liu, Po Hsiu Chien, Kenneth R. Poeppelmeier*, Vinayak P. Dravid*, Michael J. Bedzyk*, Julia E. Medvedeva*, Yan Yan Hu*, Antonio F Facchetti*, Tobin J. Marks*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

5 Scopus citations

Abstract

In this contribution, the structural and electronic effects of fluoride doping in both crystalline and amorphous indium oxides are investigated by both experimental and theoretical techniques. Pristine crystalline and amorphous fluoride-doped indium oxide (F:In-O) phases were prepared by solution-based combustion synthesis and sol-gel techniques, respectively. The chemical composition, environment, and solid-state microstructure of these materials were extensively studied with a wide array of state-of-the-art techniques such as UV-vis, X-ray photoelectron spectroscopy, grazing incidence X-ray diffraction, 19F and 115In solid-state NMR, high-resolution transmission electron microscopy (HR-TEM), and extended X-ray absorption fine structure (EXAFS) as well as by density functional theory (DFT) computation combined with MD simulations. Interestingly, the UV-vis data reveal that while the band gap increases upon F-doping in the crystalline phase, it decreases in the amorphous phase. The 19F solid-state NMR data indicate that upon fluorination, the InO3F3 environment predominates in the crystalline oxide phase, whereas the InO4F2 environment is predominant in the amorphous oxide phase. The HR-TEM data indicate that fluoride doping inhibits crystallization in both crystalline and amorphous In-O phases, a result supported by the 115In solid-state NMR, EXAFS, and DFT-MD simulation data. Thus, this study establishes fluoride as a versatile anionic agent to induce disorder in both crystalline and amorphous indium oxide matrices, while modifying the electronic properties of both, but in dissimilar ways.

Original languageEnglish (US)
Pages (from-to)3253-3266
Number of pages14
JournalChemistry of Materials
Volume34
Issue number7
DOIs
StatePublished - Apr 12 2022

Funding

We thank the Northwestern U. MRSEC grant NSF-DMR 1720139 for support of this research. J.E.M. thanks NSF-DMREF grants DMR-1729779 and DMR-1842467 for support and NSF-MRI grant OAC-1919789 for computational facilities. Y.-Y.H. acknowledges support from the NSF under grant DMR-1847038. Solid-state NMR experiments were carried out at the National High Magnetic Field Laboratory, which is supported by the NSF through NSF/DMR-1644779 and the State of Florida. This work made use of the EPIC, Keck-II, and/or SPID facility(ies) of Northwestern University’s NUANCE Center, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-2025633); the MRSEC program (NSF DMR-1720139) at the Materials Research Center; the International Institute for Nanotechnology (IIN); the Keck Foundation; and the State of Illinois. This work made use of the NU XRD Facility supported by MRSEC grant NSF-DMR 1720139 and SHyNE NSF ECCS-2025633. This work used the 5-BM-D beamline of the DuPont-Northwestern-Dow Collaborative Access Team (DND-CAT) located at Sector 5 of the Advanced Photon Source (APS). Special thanks to Qing Ma for EXAFS measurements conducted during remote operation of the APS. DND-CAT is supported by Northwestern University (NU), E.I. DuPont de Nemours & Co., and The Dow Chemical Company. This research used resources of the APS, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under contract no. DE-AC02-06CH11357.

ASJC Scopus subject areas

  • General Chemistry
  • General Chemical Engineering
  • Materials Chemistry

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