• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to project page

2019 Fiscal Year Research-status Report

Efficient Single Photon Emission From III-Nitride Quantum Dots

Research Project

Project/Area Number 19K15039
Research InstitutionThe University of Tokyo

Principal Investigator

Holmes Mark  東京大学, 生産技術研究所, 准教授 (90760570)

Project Period (FY) 2019-04-01 – 2021-03-31
KeywordsIII-nitride / quantum dot
Outline of Annual Research Achievements

In order to increase the photon extraction efficiency from III-nitride quantum dots, and allow for the development of more efficient single photon emitters, the design of a bullseye structure was performed for GaN/AlN quantum dots, and device fabrication was optimized and performed using e-beam lithography and reactive ion etching. For initial experiments a device structure consisting of 5 concentric annular trenches etched around a central nanowire structure was used. Such a device suppresses lateral photon emission from the QDs, and enhances the emission rate into the out-of-plane direction so that the photons can be more efficiently captured using an objective lens. Etching was performed into a sample of self-assembled GaN quantum dots that emit in the wavelength region of ~310nm. Optical characterization of processed devices revealed that, although fabrication was imperfect, a clear improvement of the photon extraction efficiency from the quantum dots could be realized. Statistical data was measured from several devices (>100), and the average enhancement ratio was measured to be ~6.9 (into a lens with a numerical aperture of 0.4), relative to quantum dots in unprocessed areas of the sample. In some cases sharp emission peaks could be observed, which are promising signs for the isolation of emission from individual quantum dots.

Current Status of Research Progress
Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

Devices have been designed and successfully fabricated. The fabricated devices clearly exhibit an increase in the photon extraction efficiency (which has been confirmed from testing a large number of devices). Further simulation work has shown that (using somewhat unrealistic device design involving an underlying mirror) extraction efficiencies exceeding 90% may be achievable for lenses with numerical apertures of >0.9.

Strategy for Future Research Activity

Work will proceed in two main paths: both experimentally and theoretically. This will include the experimental spectral isolation of a single quantum dot within a structure such that single photons can be extracted with high efficiency. Further design of the devices (with different spatial geometry and annular frequency) will also be performed to test if enhanced emission could be achieved with easier device fabrication.

  • Research Products

    (3 results)

All 2020 2019

All Presentation (3 results) (of which Int'l Joint Research: 1 results,  Invited: 1 results)

  • [Presentation] GaN 量子ドット Bullseye 構造の光子高取り出し効率化の検討2020

    • Author(s)
      青木伴晋, 高亢, 有田宗貴, 荒川泰彦, ホームズマーク
    • Organizer
      第67回応用物理学会春季学術講演会
  • [Presentation] 窒化ガリウム量子ドットからの光子の高取り出し効率構造の作製2019

    • Author(s)
      青木伴晋, 高亢, 有田宗貴, 荒川泰彦, ホームズマーク
    • Organizer
      第80回応用物理学会秋季学術講演会
  • [Presentation] Realizing High Quality Single Photon Emission from III-Nitride Quantum Dots2019

    • Author(s)
      M. Holmes , K. Gao , M. Arita , and Y. Arakawa
    • Organizer
      7th International Workshop on Epitaxial Growth and Fundamental Properties of Semiconductor Nanostructures
    • Int'l Joint Research / Invited

URL: 

Published: 2021-01-27  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi