# Infrared Near-Field Spectroscopy of AlGaN/GaN Heterostructures for Probing Two-Dimensional Electron Gas

https://mdr.nims.go.jp/datasets/6991b1ee-5669-4cb5-96fb-f50f8333cd99

## Files

- [Bisignano-ACSAMI25_nano-FTIR.pdf](https://mdr.nims.go.jp/filesets/1d241a8d-2eba-4201-8b2b-583428194b39/download) ([Detail](https://mdr.nims.go.jp/filesets/1d241a8d-2eba-4201-8b2b-583428194b39.md))

## Id

6991b1ee-5669-4cb5-96fb-f50f8333cd99

## Local identifier



## Visibility

open_to_public

## State

published

## Created at

2025-11-07T07:12:24.271546Z

## Updated at

2025-11-10T03:30:06.241712Z

## Published at

2025-11-10T03:24:32.051595Z

## Doi



## First published url

https://doi.org/10.1021/acsami.5c12417

## Date published

2025-09-03

## Recorded date published

2025-9-3

## Resource type

journal_article

## Manuscript type

vor

## Collection



## Title

- title: Infrared Near-Field Spectroscopy of AlGaN/GaN Heterostructures for Probing
    Two-Dimensional Electron Gas
  title_type: original
  lang: en

## Description

- description: Infrared near-field spectroscopy, or nano-FTIR, offers nanoscale resolution
    in three dimensions to probe the chemical and physical properties of samples,
    making it a unique characterization tool. This nanoscopic resolution in three-dimension
    is particularly suitable to probe two-dimensional electron gas (2DEG) where a
    2DEG has an effective thickness of a few nanometers and exists a few tens of nanometers
    below the capping layer. This work employs nano-FTIR spectroscopy to non-invasively
    probe the 2DEG of AlGaN/GaN heterostructures which are crucial for high-power
    electronic devices and sensing applications. Higher harmonic amplitude and phase
    of the nano-FTIR spectra are sensitive enough to the carrier concentration of
    the 2DEGs, which is supported by the analytical calculations based on the finite
    dipole model. A comparative analysis confirms that incorporating the 2DEG layer
    into the model is essential to match spectral features with experimental observations.
    Furthermore, hyperspectral imaging of a cross-sectional sample provides a visual
    representation of the 2DEG. The findings demonstrate that nano-FTIR enables the
    characterization of 2DEG in AlGaN/GaN heterostructures with nanometric resolution
    in ambient conditions, hence expanding its applicability in the study of such
    systems.
  description_type: abstract
  lang: und

## Creator

- name: Ilario Bisignano
  role: author
  orcid: https://orcid.org/0009-0004-9964-2106
  organization: National Institute for Materials Science
- name: Masataka Imura
  role: author
  orcid: https://orcid.org/0000-0002-4236-9549
  organization: National Institute for Materials Science
- name: Nicholaus Kevin Tanjaya
  role: author
  orcid: https://orcid.org/0000-0003-4126-8540
  organization: National Institute for Materials Science
- name: Ming-Jyun Ye
  role: author
- name: Noriyuki Okada
  role: author
  organization: National Institute for Materials Science
- name: Satoshi Ishii
  role: author
  orcid: https://orcid.org/0000-0003-0731-8428
  organization: National Institute for Materials Science

## Contact agent



## Publisher

organization: American Chemical Society (ACS)

## Managing organization



## Keyword

- subject: Two-dimensional electron gas
  schema: not_defined
- subject: AlGaN/GaN
  schema: not_defined
- subject: Nano-FTIR
  schema: not_defined
- subject: Infrared spectroscopy
  schema: not_defined

## Rights

- identifier: https://creativecommons.org/licenses/by/4.0/

## Other identifier(s)



## Data origin

- data_origin_type: other

## Embargo



## Journal

- title: ACS Applied Materials & Interfaces
  issn: '19448252'
  volume: '17'
  issue: '35'
  start_page: 50077
  end_page: 50084

## Conference



## Related item



## Funding

- identifier: 22H01917
  funder_name: Japan Society for the Promotion of Science
- identifier: 24K21723
  funder_name: Japan Society for the Promotion of Science
- identifier: JPMJFR2139
  funder_name: Fusion Oriented REsearch for disruptive Science and Technology

## Instrument



## Instrument operator



## Instrument managing organization



## Measurement method



## Specimen



## Chemical composition



## Structure for specimen



## Structural feature for specimen



## Specific property for specimen



## Process for specimen treatment



## Computational method



## Energy level/transition state



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## Fileset

- id: 1d241a8d-2eba-4201-8b2b-583428194b39
  filename: Bisignano-ACSAMI25_nano-FTIR.pdf
  content_type: application/pdf
  size: 4631673
  md5: 9c85f57b684bcf1d8fb4c3c377d419ff

## Thumbnail

fileset_id: 1d241a8d-2eba-4201-8b2b-583428194b39
filename: Bisignano-ACSAMI25_nano-FTIR.pdf