Skip to content
6CCVD Research

Band alignment of indium tin oxide (ITO) and aluminum-doped zinc oxide (AZO) on non-hydrogenated and H-terminated (100) diamond

At a Glance

Section titled ā€œAt a Glanceā€
MetadataDetails
Publication Date2025-05-23
JournalJournal of Applied Physics
AuthorsHsiao-Hsuan Wan, Chao-Ching Chiang, Jian-Sian Li, F. Ren, S. J. Pearton
InstitutionsUniversity of Florida

Abstract

Section titled ā€œAbstractā€

We report the band alignments of ITO/diamond and AZO/diamond heterostructures, comparing hydrogen-terminated (H-diamond) and non-hydrogenated (O-diamond) surfaces using x-ray photoelectron spectroscopy (XPS). For O-terminated diamond, both ITO and AZO exhibit a type II (staggered gap) alignment, with valence band offsets (VBOs) of āˆ’0.13 Ā± 0.03 eV and āˆ’0.86 Ā± 0.18 eV, respectively. In contrast, H-termination induces a transition to the type I (nested) alignment, with significantly reduced VBOs (<0.2 eV). Surprisingly, despite the negative electron affinity (NEA) of H-diamond, its conduction band minimum (CBM) lies below that of ITO/AZOā€”a reversal from the O-terminated case. This shift is attributed to the strong upward movement of the valence band maximum (VBM) in H-diamond (3.32 Ā± 0.60 eV vs 1.29 Ā± 0.20 eV for O-diamond), which lowers the CBM relative to the oxide layers. Additionally, H-termination minimizes interfacial disorder and Fermi-level pinning, facilitating a band alignment favorable for Ohmic contact formation. These findings demonstrate that while NEA influences vacuum-level positioning, interfacial band bending and VBM shifts dominate heterojunction energetics. The reduced offsets on the H-terminated surfaces suggest that ITO/AZO interlayers can enhance hole injection in diamond-based devices, offering a pathway to improved Ohmic contacts in high-power electronics.

Tech Support

Section titled ā€œTech Supportā€

Original Source

Section titled ā€œOriginal Sourceā€

References

Section titled ā€œReferencesā€
  1. 2018 - Vertical-type two-dimensional hole gas diamond metal oxide semiconductor field-effect transistors [Crossref]
  2. 2017 - Normally-Off C-H diamond MOSFETs with partial C-O channel achieving 2-kV breakdown voltage [Crossref]
  3. 2020 - Charge-carrier mobility in hydrogen-terminated diamond field-effect transistors [Crossref]
  4. 2021 - (111) vertical-type two-dimensional hole gas diamond MOSFETs with hexagonal trench structures [Crossref]
  5. 2021 - Diamond for electronics: Materials, processing and devices [Crossref]
  6. 2020 - Diamond power devices: State of the art, modelling, figures of merit and future perspective [Crossref]
  7. 2021 - Inversion-type p-channel diamond MOSFET issues [Crossref]
  8. 2017 - Durability-enhanced two-dimensional hole gas of C-H diamond surface for complementary power inverter applications [Crossref]
  9. 2022 - C-Si interface on SiO2/(111) diamond p-MOSFETs with high mobility and excellent normally off operation [Crossref]
  10. 2020 - Charge-carrier mobility in hydrogen terminated diamond field-effect transistors [Crossref]

Reads Similar to This

Quantum error correction with spins in diamond The nā€“Si/pā€“CVD Diamond Heterojunction Analysis and improvement of self-heating effect based on GaN HEMT devices