Rolled-up SiOx/SiNx microtubes with an enhanced quality factor for sensitive solvent sensing

Pengfei Song, Cheng Chen, Juntian Qu, Pengfei Ou, M. H.T. Dastjerdi, Zetian Mi, Jun Song, Xinyu Liu

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)


The microtubes made through rolling-up of strain-engineered nanomembranes have received growing research attention after their first invention due to the technology's high flexibility, integrability, and versatility. These rolled-up microtubes have been used for a variety of device applications including sensors, batteries and transistors, among others. This paper reports the development of highly sensitive whispering-gallery mode (WGM) chemical sensors based on rolled-up microtube optical microcavities (RUM-OCs). For the first time, such microcavities were batch fabricated through rolling-up of plasma-enhanced chemical vapor deposition (PECVD)-synthesized SiOx/SiNx bilayer nanomembranes, which have better optical properties than the conventional electron-beam-deposited SiO/SiO2 bilayers. Benefiting from the high refractive index (RI) of PECVD-deposited SiNx, our RUM-OC shows an enhanced quality factor of 880 that is much higher than that (50) of a SiO/SiO2 RUM-OC with the same dimensions. The developed RUM-OC is used for sensitive WGM solvent sensing, and demonstrate a limit of detection of 10-4 refractive index unit (RIU), which is 10 times lower than that (10-3 RIU) of a SiO/SiO2 RUM-OC.

Original languageEnglish
Article number415501
Issue number41
Publication statusPublished - 3 Aug 2018
Externally publishedYes


  • chemical and biosensors
  • optical cavity
  • plasma-enhanced chemical vapor deposition
  • rolled-up microtube
  • whispering-gallery mode

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