The effect of strain relaxation on electron transport in undoped Al0.25Ga0.75N/GaN heterostructures

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LİŞESİVDİN S. B., Yildiz A., ACAR S., Kasap M., Oezcelik S., Oezbay E.

PHYSICA B-CONDENSED MATTER, cilt.399, sa.2, ss.132-137, 2007 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 399 Sayı: 2
  • Basım Tarihi: 2007
  • Doi Numarası: 10.1016/j.physb.2007.05.036
  • Dergi Adı: PHYSICA B-CONDENSED MATTER
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.132-137
  • Gazi Üniversitesi Adresli: Evet

Özet

The two-dimensional electron gas (2DEG) transport properties of two-step growth undoped Al0.25Ga0.75N/GaN heterostructures with semi-insulating buffer, grown by MOCVD, were investigated in a temperature range of 20-350K. Using the quantitative mobility spectrum analysis (QMSA) method, it was shown that significant parallel conduction does not occur in worked structures. In-plain growth axis strains are calculated using the total polarization-induced charge density taken as the sheet carrier density measured from the Hall effect. It was found that the calculated strain values are in good agreement with those reported. Influences of the two-step growth parameters such as growth ramp time, the annealing temperature of the GaN nucleation layer on the mobility, and density of the 2DEG are also discussed. (c) 2007 Elsevier B.V. All rights reserved.