Influences of ALD Al2O3 on the surface band-bending of c-plane, Ga-face GaN

Jiarui Gong, Kuangye Lu, Jisoo Kim, Tien Khee Ng, Donghyeok Kim, Jie Zhou, Dong Liu, Jeehwan Kim, Boon S. Ooi, Zhenqiang Ma

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


The recently demonstrated approach of grafting n-type GaN with p-type Si or GaAs, by employing ultrathin Al2O3 at the interface, has shown the feasibility to overcome the poor p-type doping challenge of GaN. However, the surface band-bending of GaN that could be influenced by the Al2O3 has been unknown. In this work, the band-bending of c-plane, Ga-face GaN with ultrathin Al2O3 deposition at the surface of GaN was studied using X-ray photoelectron spectroscopy (XPS). The study shows that the Al2O3 can help suppress the upward band-bending of the c-plane, Ga-face GaN with a monotonic reduction trend from 0.48 eV down to 0.12 eV as the number of Al2O3 deposition cycles increases from 0 to 20. The study further shows that the band-bending can be mostly recovered after removing the Al2O3 layer, concurring that the introduction of ultrathin Al2O3 is the main reason for the surface band-bending modulation.
Original languageEnglish (US)
JournalJapanese Journal of Applied Physics
StatePublished - Nov 25 2021

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)


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