Phonons in strained AlGaN/GaN superlattices

• Phonons in strained AlGaN/GaN superlattices (SLs) with constant periods but different Al composition have been studied using a combination of infrared spectroscopic ellipsometry and Raman scattering spectroscopy. The following SL modes were identified: i) AlGaN localized E1(TO) modes identified for the first time and AlGaN localized A1 (LO) phonons; ii) GaN localized E2, E1(TO) and A1(LO) phonons; iii) delocalized E1(LO) phonons; iv) A1(TO) phonon; v) two modes around 660 cm-1 and 594-625 cm-1, respectively, not predicted by theory. The effects of strain and composition on the phonon frequencies were established and discussed.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Materialteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering (hsv//eng)

Keyword

Al compositions

AlGaN/gaN

Blue lasers

Infrared spectroscopic ellipsometry

International symposium

Raman scattering spectroscopy

Publication and Content Type

ref (subject category)

art (subject category)