# Metal-free, single-component white-light emission and visible-near-infrared whispering gallery mode micro-emitters

https://mdr.nims.go.jp/datasets/0e7eac56-0146-4ad8-9c19-e1e2b058abac

## File

- [Revised Manuscript- RSC interfaces_Final.docx](https://mdr.nims.go.jp/filesets/bd9d3451-2d0a-45bd-acda-396e2ef0385d/download) ([Detail](https://mdr.nims.go.jp/filesets/bd9d3451-2d0a-45bd-acda-396e2ef0385d.md))
- [ESI_RSC Applied Interfaces_WCPM-microcavity_clean copy.docx](https://mdr.nims.go.jp/filesets/03d56503-e5ad-4770-98d8-1b8c2e6a05fa/download) ([Detail](https://mdr.nims.go.jp/filesets/03d56503-e5ad-4770-98d8-1b8c2e6a05fa.md))

## Id

0e7eac56-0146-4ad8-9c19-e1e2b058abac

## Local identifier



## Visibility

open_to_public

## State

published

## Created at

2026-10-05T10:24:31.850010Z

## Updated at

2026-10-05T10:33:08.668832Z

## Published at

2026-10-06T01:22:54.391008Z

## Doi

https://doi.org/10.48505/nims.8638

## First published url

https://doi.org/10.1039/d6lf00065g

## Date published

2026-09-04

## Recorded date published



## Resource type

journal_article

## Manuscript type

accepted_manuscript

## Collection



## Title

- title: Metal-free, single-component white-light emission and visible-near-infrared
    whispering gallery mode micro-emitters
  title_type: original
  lang: en

## Description

- description: Single-component, metal-free white light emitters with integrated photonic
    functionalities are highly attractive for solid-state lighting and integrated
    photonic applications. Here, we report carbonized polymer microspheres that exhibit
    efficient singlecomponent white light emission (WLE) together with excitation-tunable
    visible-to-nearinfrared (VIS-NIR) whispering gallery mode (WGM) emission. The
    microspheres are synthesized via a hydrothermal crosslinking reaction between
    the natural peptide ε-poly-Llysine and citric acid, yielding smooth microcavities
    with bright cyan emission. Incorporation of ortho-phenylenediamine (OPD) during
    synthesis enables control over the internal structure and promotes the in-situ
    formation of phenazine-like polycyclic aromatic hydrocarbon (PAH) domains. The
    extended π-conjugation of the PAHs enhances visible-light absorption, leading
    to emission spanning the visible to NIR spectral region. Upon ultraviolet excitation,
    the microspheres exhibit broadband single-component WLE arising from efficient
    intracavity energy transfer. The smooth spherical morphology and heterogeneous
    aromatic domains provide strong optical confinement and excitation wavelength
    dependent emission, resulting in amplified spontaneous emission mediated by WGM
    resonances. By varying the excitation wavelength, WGM-assisted emission spanning
    the entire VIS-NIR spectral region is achieved. This work introduces a rare-earth-and
    metal-free carbonized polymer microcavity platform that integrates WLE with tunable
    WGM amplification, offering new opportunities for multifunctional optoelectronic
    and photonic devices.
  description_type: abstract
  lang: und

## Creator

- name: Barun Kumar Barman
  role: author
  orcid: https://orcid.org/0000-0002-9894-1890
- name: Keisuke Watanabe
  role: author
  orcid: https://orcid.org/0000-0002-4285-2135
- name: Vijayakumar Balakrishnan
  role: author
- name: Keiko Okano
  role: author
- name: Kenzo Deguchi
  role: author
- name: Shinobu Ohki
  role: author
  orcid: https://orcid.org/0000-0002-7357-3833
- name: Kenjiro Hashi
  role: author
  orcid: https://orcid.org/0000-0002-9472-4098
- name: Atsushi Goto
  role: author
  orcid: https://orcid.org/0000-0002-0320-4768
- name: Tadaaki Nagao
  role: author
  orcid: https://orcid.org/0000-0002-6746-2686

## Contact agent



## Publisher

organization: Royal Society of Chemistry (RSC)

## Managing organization



## Keyword

- subject: Carbonized polymer microspheres
  schema: not_defined
- subject: white light emission
  schema: not_defined
- subject: near-infrared
  schema: not_defined
- subject: whispering gallery mode
  schema: not_defined
- subject: microcavities
  schema: not_defined
- subject: amplified spontaneous emission
  schema: not_defined

## Rights

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

## Other identifier(s)



## Data origin



## Embargo



## Journal

- title: RSC Applied Interfaces
  issn: '27553701'

## Conference



## Related item



## Funding

- identifier: 24K17589
  funder_name: Japan Society for the Promotion of Science

## 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



## Software



## Custom property



## Fileset

- id: bd9d3451-2d0a-45bd-acda-396e2ef0385d
  filename: Revised Manuscript- RSC interfaces_Final.docx
  content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
  size: 12890896
  md5: 3b02e2ac45a5031961d45c04c373c0a1
- id: 03d56503-e5ad-4770-98d8-1b8c2e6a05fa
  filename: ESI_RSC Applied Interfaces_WCPM-microcavity_clean copy.docx
  content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
  size: 1482396
  md5: 9bca333d1f1929070cef06bb6db52b4d

## Thumbnail

fileset_id: bd9d3451-2d0a-45bd-acda-396e2ef0385d
filename: Revised Manuscript- RSC interfaces_Final.docx