HVPE growth of AlxGa1-xN templates for UV-LED applications

Chi Tsung Tsai*, Jia Hao Liang, Tsung Yen Tsai, Ray-Hua Horng, Dong Sing Wuu

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


In this work, the AlxGa1-xN-on-sapphire template was successfully prepared by halide vapor phase epitaxy (HVPE) at 1100°C. The flow ratio (R) of the HCl flow rate through Al metal to the total HCl flow rates through Al and Ga metals was adjusted to control the Al content. The AlxGa1-xN films without phase separation can be obtained as the R value exceeds 0.67. The low R value strongly enhances the formation probability of GaN instead of AlxGa1-xN. This indicates that a sufficient concentration of the Al precursor is certainly vital for the formation of AlxGa1-xN compounds. The AlxGa1-xN prepared at the R value of 0.80 can achieve best crystallinity and the lowest surface roughness. Furthermore, the optical transmittance of the AlxGa1-xN under R=0.80 is above 70% between the wavelength of 225 nm and 400 nm. As a result, the AlxGa1-xN under R=0.80 can be regarded as a suitable growth template for the ultraviolet light-emitting diodes. The internal quantum efficiency of the 370 nm-quantum wells on the AlxGa1-xN/sapphire prepared under R=0.80 shows 127% improvement as compared with that on the undoped-GaN/sapphire.

Original languageEnglish
Title of host publicationGallium Nitride Materials and Devices X
EditorsJen-Inn Chyi, Hiroshi Fujioka, Hadis Morkoc
ISBN (Electronic)9781628414530
StatePublished - 13 Mar 2015
EventGallium Nitride Materials and Devices X - San Francisco, United States
Duration: 9 Feb 201512 Feb 2015

Publication series

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


ConferenceGallium Nitride Materials and Devices X
CountryUnited States
CitySan Francisco


  • AlGaN template
  • HVPE
  • internal quantum efficiency
  • LED
  • optical
  • transmittance
  • ultraviolet

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