Infrared dielectric functions and optical phonons of wurtzite YxAl1-xN (0 less than= x less than= 0.22)
2015 (English)In: Journal of Physics D: Applied Physics, ISSN 0022-3727, E-ISSN 1361-6463, Vol. 48, no 41, 415102- p.Article in journal (Refereed) Published
YAlN is a new member of the group-III nitride family with potential for applications in next generation piezoelectric and light emitting devices. We report the infrared dielectric functions and optical phonons of wurtzite (0001) YxAl1-xN epitaxial films with 0 less than= x less than= 0.22. The films are grown by magnetron sputtering epitaxy on c-plane Al2O3 and their phonon properties are investigated using infrared spectroscopic ellipsometry and Raman scattering spectroscopy. The infrared-active E-1(TO) and LO, and the Raman active E-2 phonons are found to exhibit one-mode behavior, which is discussed in the framework of the MREI model. The compositional dependencies of the E-1(TO), E-2 and LO phonon frequencies, the high-frequency limit of the dielectric constant, epsilon(infinity), the static dielectric constant, epsilon(0), and the Born effective charge Z(B) are established and discussed.
Place, publisher, year, edition, pages
IOP PUBLISHING LTD , 2015. Vol. 48, no 41, 415102- p.
YAlN; phonons; infrared dielectric function
Physical Sciences Chemical Sciences
IdentifiersURN: urn:nbn:se:liu:diva-122192DOI: 10.1088/0022-3727/48/41/415102ISI: 000362007100004OAI: oai:DiVA.org:liu-122192DiVA: diva2:865062
Funding Agencies|Swedish Research Council (VR) [2013-5580]; Swedish Governmental Agency for Innovation Systems (VINNOVA) [2011-03486]; Swedish Foundation for Strategic Research (SSF) [2012FFL12-0181]; National Science Foundation [MRSEC DMR-0820521, EPS-1004094]; Stiftelsen Lars Hiertas Minne [FO2013-0587]; [RECI/FIS-NAN/0183/2012 (FCOMP-01-0124-FEDER-027494)]2015-10-262015-10-232016-08-31