Determination of the LO phonon energy by using electronic and optical methods in AlGaN/GaN


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Celik O., Tiras E., Ardali S., LİŞESİVDİN S. B. , ÖZBAY E.

CENTRAL EUROPEAN JOURNAL OF PHYSICS, vol.10, no.2, pp.485-491, 2012 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 10 Issue: 2
  • Publication Date: 2012
  • Doi Number: 10.2478/s11534-011-0100-x
  • Title of Journal : CENTRAL EUROPEAN JOURNAL OF PHYSICS
  • Page Numbers: pp.485-491

Abstract

The longitudinal optical (LO) phonon energy in AlGaN/GaN heterostructures is determined from temperature-dependent Hall effect measurements and also from Infrared (IR) spectroscopy and Raman spectroscopy. The Hall effect measurements on AlGaN/GaN heterostructures grown by MOCVD have been carried out as a function of temperature in the range 1.8-275 K at a fixed magnetic field. The IR and Raman spectroscopy measurements have been carried out at room temperature. The experimental data for the temperature dependence of the Hall mobility were compared with the calculated electron mobility. In the calculations of electron mobility, polar optical phonon scattering, ionized impurity scattering, background impurity scattering, interface roughness, piezoelectric scattering, acoustic phonon scattering and dislocation scattering were taken into account at all temperatures. The result is that at low temperatures interface roughness scattering is the dominant scattering mechanism and at high temperatures polar optical phonon scattering is dominant.