Suppression of indium clustering and quantum confined stark effect of InGaN LED on silicon (111)

Richard Liu, Callan McCormick, Can Bayram

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Optical properties of InGaN/GaN multi-quantum-well (MQWs) grown on sapphire and on Si(111) are reported. The tensile strain in the MQW on Si is shown to be beneficial for indium incorporation and Quantum-confined Stark Effect reduction in the multi-quantum wells. Raman spectroscopy reveals compressive strains of -0.107% in MQW on sapphire and tensile strain of +0.088% in MQW on Si. Temperature-dependent photoluminescence shows in MQW on sapphire a strong (30 meV peak-to-peak) S-shaped wavelength shift with decreasing temperature (6 K to 300K), whereas MQW on Si luminescence wavelength is stable and red-shifts monotonically. Micro-photoluminescence mapping over 200 by 200 μm2 shows the emission wavelength spatial uniformity of MQW on Si is 2.6 times higher than MQW on sapphire, possibly due to a more uniform indium incorporation in the multi-quantum-wells as a result of the tensile strain in MQW on Si. A positive correlation between emission energy and intensity is observed in MQW on sapphire but not in those on Si. Despite the lower crystal quality of MQW on Si revealed by atomic force microscopy, it exhibits a higher internal quantum efficiency (IQE) than MQW on sapphire from 6 K to 250 K, and equalizes at 300 K. Overall, MQW on Si exhibits a high IQE, higher wavelength spatial uniformity and temperature stability, while providing a much more scalable platform than MQW on sapphire for next generation integrated photonics.

Original languageEnglish (US)
Title of host publicationGallium Nitride Materials and Devices XIV
EditorsUlrich T. Schwarz, Hadis Morkoc, Hiroshi Fujioka
ISBN (Electronic)9781510624788
StatePublished - 2019
EventGallium Nitride Materials and Devices XIV 2019 - San Francisco, United States
Duration: Feb 4 2019Feb 7 2019

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


ConferenceGallium Nitride Materials and Devices XIV 2019
Country/TerritoryUnited States
CitySan Francisco


  • AlGaN buffer layer
  • IQE
  • Indium incorporation
  • MQW
  • Quantum confined stark effect
  • Silicon

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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